INVESTIGATING THE ARCHITECT OF GRAND MOSQUE OF AL-MASHUN MEDAN, NORTH SUMATRA, INDONESIA – PART 1

This study aimed to investigate the architect of the Grand Mosque of AlMashun Medan, North Sumatra, Indonesia. Four persons are alleged to be the architect of the mosque, which was built by the Sultan of Deli, Makmun Al-Rasyid Perkasa Alamsyah from 1906-1909. Their names are Adolf J. Dingemans, J.A. Tiendemans, Klingenberg, and Theo van Erp. All of them are Dutch. However, who was the real architect of the mosque remains uncertain. The four names are mentioned in many sources, but no evidence or argumentation is provided. The attributions will be critically examined to find out who is the most likely candidate. The method of this research was a critical review and descriptive analysis of all the collected information, and the interpretation of some physical evidence from the field survey. However, this research did not find who indeed the architect of the Grand Mosque of Al -Mashun Medan. The attribution still needs to carefully investigated because the more definite evidence is still required. It only found that the most convincing assumption is that the architect of the mosque is Theo van Erp.


INTRODUCTION
Beside the Maimoon Palace, the Grand Mosque of Al-Mashun is the most important architectural heritage building of the Deli Sultanate in Medan, North Sumatra, Indonesia.The construction of the mosque was started on August 21, 1906, and it was ready to be inaugurated on September 9, 1909.The building was initiated and financed by the Deli Sultanate and the Dutch Deli Spoorweg Maatschappij in East Sumatra.It was built as the ultimate celebration of their profitable partnership in Sumatra in the Dutch East Indies era.This work of architecture became the symbol of the very close relationship between the Deli Sultan as a local ruler and the Dutch authority in East Sumatra in the early twentieth century [1].
The local community still uses the Grand Mosque of Al-Mashun for daily and Friday prayers.The mosque is a landmark in Medan city today.It is located on Sisingamangaraja Street and Masjid Raya Street, about three hundred meters from the location of the Maimoon Palace [2].Many of the building materials were imported from Europe, for example, its marble was taken from Italy.
The design of the mosque also contrasts with local mosque architecture in Sumatra and Nusantara (the Indonesian archipelago) until the 19th century.Local mosques generally had traditional tiered pyramidal roofs, were made of wood, and did not have a dome or minaret or arches [3].The Grand Mosque of Al-Mashun has domed roofs, is made of bricks and marble, and has columns and arches that are heavily influenced by Mughal (Indian) and Moorish (Andalusia) architecture (See figures 1-3) [4] [5].
The main dome of the Grand Mosque of Al-Mashun has a flat and octagonal shape and is in the center of the building.Four domes surround it with a lower height than the main dome.On the peak of the dome roof, there is the usual crescent moon decoration that is usually found on mosque buildings in other regions.Dome-roofed mosques started appearing in Sumatra under Dutch colonial authority since the middle of the 19th century [6] [7].
According to several sources, a Dutch architect was appointed to work on the design and planning of the Grand Mosque of Al-Mashun.However, the name of the architect in question is still uncertain.There is a great deal of confusing and even contradictory information on this subject, either in articles, books, papers, and from oral sources.
Therefore, this study aimed to discover the identity of the architect of the grand mosque.'The architect' in this paper is the designer or creator of the architectural form and spatial ideas of the mosque, not an architect who worked on the construction or a designer of one element or part of the building.
During our investigation, four names emerged as the alleged architect of the mosque.They are 1) Adolf J. Dingemans, 2) J.A. Tiendemans, 3) Klingenberg, and 4) Theo van Erp.This study focused on critically examining who the actual architect could be.Each of these names will be discussed in detail in this paper, and at the same time, logical arguments will be provided, along with as much as possible reference data.Obstacles in this study were that authentic/ original drawings/blueprints and old documents/texts/ articles such as newspapers or magazines that were published contemporaneously, contract documents, or other valuable historical sources had not been found up to the writing of this paper, so we had to rely on referenced sources in the form of books or articles, etc.However, this preliminary investigation is expected to give an idea of who is most likely the architect of the mosque.

METHODS
For this research, as much as possible data and information was collected based on 1) literature, internet, books, articles, papers, and old documents related to the history of the Deli Sultanate in the Dutch East Indies era and the Grand Mosque of Al-Mashun, 2) a field survey, searching for plaques/evidence of the architect's name and its construction history, and taking photos, and 3) an interview with the grand mosque's manager and Maimoon Palace staff/guides.The method of analysis was a critical review and descriptive analysis of all the collected information, and interpretation of some physical evidence from the field survey.The research was done by going over the various possibilities and looking for proof or logical arguments much like a detective.This investigation also cites and criticizes previous opinions by providing counter-evidence.

HISTORICAL BACKGROUND OF THE GRAND MOSQUE OF AL MASHUN THE EMERGING OF DELI SULTANATE
Based on historical records, in the 16th century, there was a kingdom called Aru with its center located in Deli Tua to the south of what now is Medan city.The Aceh Sultanate, under Sultan Iskandar Muda, appointed Tuanku Gocah Pahlawan to defeat the Aru Kingdom in 1612.Tuanku Gocah Pahlawan with the title of Laksamana Kuda Bintan became the representative of the Aceh Sultanate to rule the former territory of Aru in East Sumatra.In 1632, the Aceh Sultanate established the Deli Sultanate, and Tuanku Gocah Pahlawan was appointed as the first king.He founded many new villages under his rule [8].
The first king of the Deli Sultanate died in 1669 and was succeeded by his son Tuanku Panglima Perunggit.In this period, the Deli Sultanate claimed independence from the Aceh Sultanate and the center of the kingdom was moved to Labuhan Deli, about 20 km to the north from where Maimoon Palace is now located in Medan.See figure 4 [9].
The eighth ruler of the Deli Sultanate was Sultan Mahmud Perkasa Alam, who ruled from 1858-1873, and developed a close relationship with the Dutch colonial authority.He was succeeded by Sultan Makmun Al-Rasyid Perkasa Alamsyah, who ruled from 1873-1924, when massive tobacco plantations were developed by several privately owned companies, especially the Deli Maatschappij.The relationship between the Deli Sultanate and the Dutch authority became even more close and intimate .
The tobacco trade expanded rapidly.This made the Deli Sultanate very rich in this period.The center of the kingdom was moved from Labuhan to Medan after the Maimoon Palace was completed on May 18, 1891.See figure 5.Then, the Sultan built the Grand Mosque of Al-Mashun in 1906.Sultan Makmun Al-Rasyid was known as a builder in early Medan at the end of 19th century [10].See figure 6.

DUTCH EAST INDIES ERA
From 1830-c.1870, Governor-General Johannes van den Bosch established profitability as the main principle of government in the Dutch East-Indies.He believed that the Dutch should restrict their attention to Java, Sumatra, and Bangka [11].He introduced the Cultuurstelsel (compulsory cultivation system), which was primarily implemented in Java, with the purpose of making the colony more profitable.The system compelled villagers to turn over part of their land for the production of crops that had been determined by Dutch colonial government or to work part of the year on government plantations.Consequently, there was a lot of poverty, hunger, worsening public health and living conditions for many farmers in Java.
The situation was entirely different in the other islands of the archipelago, where the Dutch never had serious pretensions to establish their authority [11].However, after the decline of the VOC and the short rule by the British from 1811-1816, the Dutch made substantial geographic expansions in the whole archipelago for both economic and status reasons.
The Dutch had long been interested in Sumatra, where they re-established and extended their influence in the 19th century.They occupied the East Coast of Sumatra based on a political contract with Siak Sri Indera Pura, called the Siak Treaty, on February 1, 1858 [12].When Deli was under the influence of Siak, the relationship between the Sultanate of Deli and the colonial government became increasingly stronger.
They needed each other: Deli needed security guarantees, and the Dutch wanted the natural resources that Sumatra had to offer.
The Cultuurstelsel was ended in 1870 under ongoing pressure from the liberal party who held a majority in Parliament.New laws successfully eliminated some of the characteristic features of the Cultivation System and supported a more liberal attitude toward private companies.In this period, there were more possibilities for private companies to invest and operate in the Dutch colonies.
The opening of the Suez Canal in 1869 was also very influential on the traffic intensity between the Netherlands and the Dutch East Indies during the following decades [13].consequence, Amsterdam became one of the largest tobacco markets in the world at that time.And, understandably, payments from the plantations and land rents from private companies made the Sultan of Deli a wealthy and prosperous man.
To transport tobacco from the plantations to the port, in 1883, the Deli Maatschappij established the Deli Spoorweg Maatschappij.Many Europeans came to the Dutch East Indies as tourists, including Deli Land, which produced the finest quality of tobacco in the world at that time.After becoming the capital of Deli Land in 1891, Medan quickly became a busy center of government and commercial activity, known as 'Paris in Sumatra'.To accommodate the tourists, a Dutch businessman, Aeint Herman de Boer, built Hotel De Boer in the city center of Medan in 1898.In the early 20th century, Dutch companies and the colonial government built a great deal of infrastructure and buildings in Medan, such as railways, the city hall, the Javasche Bank office building, the postal office building, residential housing, a port, and so forth [14].See figure 7.

THE ARCHITECT OF THE GRAND MOSQUE OF AL MASHUN
From the investigation, four persons are alleged to be the architect of the Grand Mosque of Al-Mashun, Medan.They are: 1) Adolf J. Dingemans from Amsterdam, more often referred to as A.J. Dingemans, 2) J.A. Tiendemans or J.A. Tingdemans, 3) Klingenberg, an architect from Amsterdam, and 4) Theodoor van Erp, also referred to as Th.van Erp or Theo van Erp, a Dutch military engineer who would play an important role in restoring the Borobudur temple.Below, these four names will be discussed in more detail as possible architects of the mosque.

ADOLF J. DINGEMANS
The name Adolf J. Dingemans or A.J. Dingemans is probably the most referenced as the architect of the Grand Mosque of Al-Mashun Medan.However, we have not found any factual proof or evidence that A.J. Dingemans is indeed the architect of the mosque.There is even proof that A.J. Dingemans most likely was not the architect of the mosque but an artist/craftsman who made only the mimbar or pulpit.
In our interview with H. Ridwan A.S. (then 60 years old), the secretary of the Badan Kemakmuran Masjid (BKM -the institution/authority that manages the mosque), he stated that the Grand Mosque Al-Mashun of Medan was designed by A.J. Dingemans, an architect from Amsterdam, referring to the plaque that is attached to a railing base of the pulpit.The name A.J. Dingemans is written in capital letters at the top, with the text 'Amsterdam,' also written in capital letters, at the bottom.See figure 8.This may be the reason that the name of A.J. Dingemans is most referenced, because anyone who visits the mosque can see this plaque.Moreover, visitors are given the explanation by the manager of the mosque that A.J. Dingemans is the architect of the mosque based on this plaque.
Also, some literature mentions that A.J. Dingemans is the architect of the mosque.In 2008, Thijs Weststeijn wrote an article entitled 'De Indische wortels van het Nederlandse modernisme: ideeën over oosterse spiritualiteit bepaalden de interesse in Indische kunst,' on page 2, in which he mentions 'Adolf Dingeman' (without s) as the architect of the mosque: "In 1906 Adolf Dingeman completed a similar entrance, to a mosque with corner towers, colonnades and richly worked 'minbar' (pulpit).Finally, in 1933, the arch was applied by Carl Wolf Schoemaker, who carefully provided his mosque with calligraphy and orientated it on Mecca.""The context of this architecture were the Dutch overseas territories.The Amsterdam building from 1883 housed a World Exhibition with a lot of attention for the colonies; scale models of Islamic architecture had a prominent place there.The mosque of Dingeman, still in full use, is in Medan in North Sumatra."[15] Another reference to Dingemans is found in an article written by Gé Prince in 2010, entitled 'Medan: Koloniale Stad Als Exponent van Het Deli-wonder' in a book entitled Stad en Regio: Opstellen Aangeboden aan prof.dr.Pim Kooij bij zijn afscheid als hoogleraar economische en sociale geschiedenis aan de Rijksuniversiteit Groningen, on page 153: "The flourishing of Medan had attracted the attention of the Deli Sultan, who, thanks to the concessions granted to tobacco companies, shared in the wealth.He settled in Labuan, located at the mouth of the Deli River.In the eighties of the nineteenth century, he moved his residence to Medan, which contributed to the status of the city.In 1888, the Maimoon Palace was commissioned by the sultan, which is now another of Medan's main attractions.
The Great Mosque of Medan, the Majid Raya, was built in 1906 according to the design of the Amsterdam architect A.J. Dingemans.The relocation of the residence of the sultan caused many Chinese traders to move to Medan." [16] In these articles, Weststeijn and Prince both mention without reservation that the architect of the Great Mosque of Medan is the Amsterdam architect A.J. Dingemans.Unfortunately, they do not provide any source, proof or argumentation.A paper from 2012 entitled 'The influence of 19th century Dutch Colonial Orientalism in spreading Kubah (Islamic Dome) and Middle-Eastern architectural styles for mosques in Sumatra' written by Kemas Ridwan Kurniawan and Ratu Arum Kusumawardhani also mentions that A.J. Dingemans is the architect of the mosque [7].Again, they do not give any source, proof or argumentation.
There are also several articles in Dutch, English, and Bahasa Indonesia written by journalists in newspapers and websites that mention A.J. Dingemans as the architect of the mosque without substantiation.Their assumption probably goes back to the plaque attached to the pulpit, which says the name of A.J. Dingemans.
However, we disagree with the opinion that the name of A.J. Dingemans being written on a plaque on the pulpit means he is the architect of the mosque.Firstly, we believe that the name probably refers to the artist, craftsman who made the pulpit, or a funder or grantor of the pulpit.We argue that if A.J. Dingemans was the architect of the mosque, a plaque with his name should have been attached prominently to a fixed part of the building, such as a wall, mihrab, or door/entrance.If the name is on part of a movable element, such as the pulpit, we believe that it very likely does not refer to the architect.See figure 9.
That Dingemans was indeed the maker of the pulpit is confirmed by the Sumatra Post on 21 May 1909 in the section 'Amsterdamsche Brieven': "Representatives of the daily newspapers have been given the opportunity to see a remarkable artwork that is destined for Deli in the art smithy of Mr. Dingemans (formerly of Vuuren) on the Overtoom.It is the dome-shaped cover of a Mimbar (pulpit) for the new mosque of the Sultan of Deli.The whole unit at 4 1/2 Meters is made of yellow copper kept in a matted tone.For half a year, 15 skilled workers have worked on it, understandably, if one sees its rich ornamentation.Mr. Kerstens, Engineer of the Deli-Spoor, made the order and was charged with the supervision of the execution.Initially, i t was decided that this beautiful piece of work would be exhibited at Sinkel on Damrak, but objections were made by the commissioner.It will be shipped one of these days."[17]  Based on this report, it is clear that A.J. Dingemans is the artist/craftsman from Amsterdam who made the pulpit.Therefore, it makes sense that the plaque was attached to a part of the minbar/pulpit and not to a fixed element of the building.Still, this does not preclude that A.J. Dingemans was the architect of the mosque.Who exactly was A.J. Dingemans?Could he have been the architect of the Grand Mosque of Medan?Was he an architect at all?These questions still need to be investigated.

J.A. TIENDEMANS
Several articles on the internet in Bahasa Indonesia mention J.A. Tiendemans (sometimes 'Tingdemans') as the architect of the Grand Mosque of Medan.This is a little bit strange because, to the best of our knowledge, this name cannot be found in any books or research papers related to the Grand Mosque of Medan in English or Dutch.However, we did find this name in a document on the Grand Mosque of Medan written by students of and supervised by the Department of Architecture University of North Sumatra (USU) with no date/year.In the header of the document, J.A. Tiendemans is mentioned as the architect of the Grand Mosque of Al-Mashun Medan.We believe that they meant to refer to A.J. Dingemans but someone probably misspelled, misheard, or mispronounced his name.

KLINGENBERG
Klingenberg is another name referred to as the architect of the Grand Mosque of Medan.This name can be found in the book entitled The History of Medan in the olden times, written by Tengku Luckman Sinar.On page 172 it is mentioned that the Grand Mosque of the Sultan of Deli was built in 1906 by Amsterdam architect Klingenberg, as follows: "This mosque of the Sultan of Deli was built in 1906 by Amsterdam architect Klingenberg, according to the wishes and creation of Sultan Makmun Al Rashid from Deli, and was first used during the Friday prayer September 10, 1909."[12] In the book entitled Jejak-jejak Islam: Kamus Sejarah Peradaban Islam dari Masa ke Masa, written by Ahmad Rofi' Usmani, it is mentioned that two architects were involved in the design of the Grand Mosque of Medan, namely Klingenberg and A.J. Dingemans [18].
Many articles on the internet written in English or Dutch also mention Klingenberg as the architect of the Grand Mosque.Some say Klingenberg only, while others refer to two architects: Klingenberg and Adolf J. Dingemans.Both are supposedly from Amsterdam.Unfortunately, none of the articles provide any substantiation.
However, there is also an online article that states that Klingenberg was an architect who worked on the construction of the mosque.It also mentions that the mosque was initially designed by Th. van Erp, who also created the Maimoon Palace in Medan and was succeeded by A.J. Dingemans when he was commissioned to restore the temple of Borobudur in Central Java.Unfortunately, it also does not provide any source, proof or argumentation.
While investigation the name of Klingenberg as the possible architect of the grand mosque, we did not find it in any old documents, texts or research papers.We found it only in some books, such as those written by Tengku Luckman Sinar and Ahmad Rofi Usmani as quoted above.However, without evidence, it is very speculative to mention Klingenberg as the architect of the grand mosque.

THEODOOR VAN ERP
From the four names, Theodoor (Theo) van Erp (1874-1958) is the most famous one.About Van Erp, more biographical details can be found because there are many more sources.Theo van Erp is a military engineer in the service of KNIL (Koninklijk Nederlands Indisch Leger) or The Royal Dutch East Indies Army.However, he is better known as the archaeologist who restored Borobudur Temple from 1907-1911, than as the alleged architect of the Grand Mosque of Medan.See figure 11.
There is a contradiction between the explanations of the Badan Kemakmuran Masjid (BKM) as the institution/authority that manages the mosque and the staff or guides at Maimoon Palace.Based on our interview with Tengku Moharsyah Nazmi (then 30 years old), a local guide of Maimoon Palace, the architect of the Grand Mosque of Al-Mashun was not A.J. Dingemans but Theo van Erp.According to his explanation, after making the design of the Maimoon Palace (1888-1891), Theo van Erp also designed the Grand Mosque of Al-Mashun.But because he got the task to restore Borobudur Temple in Central Java in 1906, the design of the grand mosque was probably continued by another architect.
This information may be based on the book by Tengku Luckman Sinar entitled The History of Medan in the olden times, which can easily be found in the Maimoon Palace complex and other historic places in Medan.However, the trustworthiness of this book is dubious because of some inconsistencies it contains.On page 172, the book mentions that the architect of the grand mosque is Klingenberg, but on page 81 and page 152, it states that the architect of the grand mosque is Th.van Erp, who was also the architect of the Maimoon Palace: "The Sultan of Deli, Makmun Al Rasjid, started occupying the Maimoon Palace on May 18, 1891, and the capital of Deli was officially moved to Medan.This palace was built on the ground of the ex-concession Mabar Deli Tua and its architect was the military engineering officer Th. van Erp, costing Fl. 1.000.000,-(memorandum of transfer of Resident C. A. Scherer 1886), who was also the architect of the Mesjid Raya.Its furniture was made by the Muter company, well known in The Hague." [12] "These were supported by the Medan Municipality at the expense of the sultanate, including the construction of the Mesjid Raya (the great mosque) and its surroundings.The architect of the Maimun palace and the Mesdjid Raya Al Mansun was a Royal Dutch East Indies Army officer, called CAPTAIN TH.VAN ERP, of the Army Engineering, who had designed lots of large buildings in Batavia."[12] Hence, the statements in this book on this particular subject are not consistent.How is it possible that a different architect is mentioned for the same mosque on different pages in the same book, Klingenberg and Th.van Erp? Are Klingenberg and Th.van Erp the same person?This is definitely impossible.Or is Klingenberg an architect who continued the early design of Th. van Erp on the Grand Mosque of Al-Mashun?The book does not mention or explain this.
The book also shows a lack of consistency and thoroughness in writing the name of the palace, the mosque, letters, and so forth.However, it explicitly mentions twice that Th. van Erp is the architect of the mosque, albeit without source, proof or argumentation.
There is an interesting note on the biography of Theo van Erp entitled Life and Works of Theo van Erp written by A.J.Th.(Guus) van Erp, dated September 29, 2011.Guus van Erp is a grandson of Th. van Erp.In the note, it is mentioned under the heading of 'KMA/Dutch Indies' (1892) that Theo van Erp designed the mosque in Medan: "Theo entered the Royal Military Academy (KMA) at Breda in 1892.In 1896 he was sent as a young second lieutenant of the Engineering Corps of the Royal Dutch Indies Army (KNIL) to the Dutch Indies, where he was deployed for some time in the unfortunate Aceh war.He was also involved in building the fortress at Cilacap and designed the mosque in Medan."[19] After van Erp's view and vision on the restoration of Borobudur Temple received support from Dr. J.L.A. Brandes -a pioneer in the Dutch East Indies archeology -van Erp was assigned to restore the Borobudur temple in Central Java from 1907-1911 [19].Based on this biographical note, in the period from 1902-1903, Theo van Erp had already worked on the Siwa temple of the Prambanan complex and the main temple of the Sewu complex.At the same time, van Erp's name is also mentioned in connection with the Ngawen, Selogriyo, and Pringapus temples [19].
Valuable information about the architect of the grand mosque is provided in the book entitled Islam at the Tropenmuseum written by Mirjam Shatanawi, specifically in Chapter 9 about Indonesia.In the acknowledgments, Shatanawi writes that the background information on the construction and opening of the great mosque at Medan was obtained from the Deli Courant, editions of II and 25 August of 1909 [20].
In Chapter 9 she writes that the architect of the Grand Mosque of Medan is Theodoor van Erp, a Dutch architect, and a military engineer.Van Erp was commissioned to make the design of the mosque as the crowning celebration of the profitable partnership between the Dutch authorities and the Deli Sultanate: "With support from the Dutch authorities, the sultan held sway over hundreds of thousands of subjects and so enabled the Deli Maatschappij its plantations.In return, he made a fortune from leasing the ground.The new mosque was the crowning celebration of their profitable partnership.The Sultan of Deli wished to erect a lasting monument even more impressive than his own palace.A Dutch architect, a military engineer Theodoor van Erp, was commissioned to make the design."[20] We believe that the Deli Courant, which was published contemporaneously to the construction of the Grand Mosque Al-Mashun of Medan, is one of the most valuable sources to investigate its history.When the Deli Courant mentions in 1909 that Theodoor van Erp was the architect who designed the mosque, this is probably reliable information.
However, it still leaves some questions.Why van Erp was chosen since he was not an architect by profession.Also, was Theodoor van Erp an archaeologist or an architect?How did he design the Maimoon Palace and the Grand Mosque Al Mashun?He was a military engineer then more commonly known as an archaeologist, especially as the one who successfully restored Borobudur temple, but he apparently was also an architect and an artist.See figure 12.
A statement of A.J. Bernet Kempers confirms this, an archeologist and former Director of Archaeology in the Dutch East Indies and Indonesia , who put it like this in one of his publications: "At the beginning of 20th century, at a very critical moment in its existence, Borobudur was lucky enough to receive care from a man who developed himself into a great restorer, an artist, and an architect as well as a scientist.""This good fortune helps Borobudur keep much of its riches and its exceptional character.
Everything might have been very different had the work not been done so well or, of course, had the monument been discounted as hopeless and not worked on at all." [19] If it is true that Theodoor van Erp was initially the architect of the mosque, and then he was assigned to restore the Borobudur Temple in Central Java in 1907, the question is whether the design was finished or continued by another architect.If another architect finished it, would that have been A.J. Dingemans and Klingenberg?This remains unclear.Evidence or proof is needed.Shatanawi in her book mentions that a Deli Spoorweg Maatschappij employee designed the mimbar (pulpit) and the mihrab (prayer niche) [20].If this is compared with the report from De Sumatra Post on 21 May 1909 in the section 'Amsterdamsche Brieven,' the Deli Spoorweg Maatschappij employee meant would have to be A.J. Dingemans from Amsterdam.Is that correct?Our investigation needs to be continued.

CONCLUSION
After this study was finished, it was still uncertain who is the architect of the Grand Mosque of Al-Mashun Medan.The attribution still needs to carefully investigated because more definite evidence is still needed.However, from the discussion in this paper, it can be seen who the most likely candidate is.The most convincing assumption is that the architect of the mosque is Theo van Erp, as mentioned in Shatanawi's book based on the Deli Courant of II and 25 August 1909.This is a trustworthy resource.However, whether Theo van Erp finished the design or only provided a design concept that was then completed by another architect, is still an open question.
The next possibility is that A.J. Dingemans is the architect of the mosque.This assumption desperately needs evidence, given the report from De Sumatra Post of 21 May 1909, where he is mentioned as the artist/craftsman who made the mimbar or pulpit for the mosque, not as the architect who designed the mosque.The third possibility is a certain Klingenberg, about whom nothing is known.He is probably an architect who played a role in the construction of the mosque.Meanwhile, the other remaining names of J.A. Tiendemans and J.A. Tingdemans are assumed to refer erroneously to A.J. Dingemans.
In order to further investigate the remaining questions, it is necessary to continue the research by carefully examining and checking original old documents, preferably original blueprints/sketches or else newspapers and magazines that were published contemporaneously.However, we do not know if any original drawings still exist.In contrast, there are three newspapers/magazines that were published and circulated in Medan at the end of the 19th century and early 20th century, i.e., the Deli Courant (first published in 1885, initially only twice a week), followed by De Sumatra Post (from 1898), and the magazine De Planter (from 1909).
We believe that there should be plenty of reporting about the mosque since it was an important building and several major events were related to its inauguration.Further study on this subject will focus on these types of old documents, which have not yet been discovered by the authors.

Figure 2 .Figure 3 .
Figure 2. The Great Mosque of Al-Mashun Medan in 2017.Photo by the author.

Figure 4 .Figure 5 .Figure 6 .
Figure 4. Location of Labuhan and Medan City in North Sumatra, Indonesia.Source: Wikipedia and developed adapted by the authors

Figure 7 .
Figure 7.The Timeline of the Grand Mosque of Al-Mashun and Medan during the Dutch East Indies era.Source: authors

a b Figure 8 .
(a) The Plaqueplaque that mentioned amentions the name of A. J. Dingemans in aboveat the top and Amsterdam inat the bottom.(b) The position of the plaque that attached at one ofto a railing base of the mimbar/pulpit.Source: authors.

Figure 9 .
Figure 9.The Mimbarmimbar or pulpit of the Grand Mosque of Al Mashun.Source: authors.