As the title implies I am wondering as to the reasons why Indonesia is a Muslim country? When visiting Indonesia a few years back, I surprisingly learnt that the country had the largest Muslim population in the world. Even though it was new information I never gave it all that much thought, but a few days ago when looking at a world map I started wondering about how it happened.

The other religions are generally bounded with some geographical connection from centralized hubs, for example Christianity in Europe, Hinduism in India etc and otherwise been spread by conquerors for example the Christianity to the Americas by the colonialism (a very broad generalization but I hope you get the idea of what I mean). And in this respect Indonesia is quite far away from the Muslim middle eastern "hub" being surrounded by countries with other major religions.

Trying to read up a bit about it I learn that Islam came to Indonesia with traders from India?? which also seems strange to me, and it also seems a bit "unusual" that the religion got rooted by simply being brought in by traders?

So why is Indonesia a Muslim country?

  • More in detail, how and why did Islam migrate to Indonesia and overtake Hinduism and Buddhism in the country?
  • How did it root in the country (from what I can understand without any forcing factor)
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    Trade. I'm going to oversimplify a complex and fascinating relationship but Islam supports and enables trade through a consistent, transparent, quasi-legal governance framework. Indonesia sits atop some fairly crucial trade routes.
    – MCW
    Commented Aug 4, 2016 at 17:08
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    "The spread of Islam was initially driven by increasing trade links outside of the archipelago. " Wikipedia
    – MCW
    Commented Aug 4, 2016 at 17:57
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    "the Muslim middle eastern "hub" being surrounded by countries with other major religions" I think you would be surprised to hear how many countries have a significant Muslim population. Also, it seems you not considered that Islam armies were pretty active in Asia (as well as Africa or Europe) conquering the land and spreading religion. While it is not necessarily the main reason for Indonesia, but it is incorrect to believe that the Middle East is the only Muslim region around.
    – Greg
    Commented Feb 28, 2017 at 5:53
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    Islam is the dominant religion in that it is practiced by the majority of the population, but Indonesia is not, and was never a Muslim country. Indonesia based its ideology in Pancasila, not any particular religion. Commented Apr 20, 2017 at 12:23
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    Related questions might be: how did India pull off not becoming muslim (considering it was ruled by muslim rulers for a time) and why, in contrast, did muslim areas in SE Asia not stay hindu or buddhist? Commented Aug 6, 2017 at 10:43

3 Answers 3


The Muslim religion started making its way into modern Indonesia in the 13th century. That's when various rulers in North Sumatra, then Java, started converting to that religion, as a result of contact with Muslim traders, and converted their subjects.

The religion got a big boost in the 15th century when the Sultan of Malacca (modern west Malaysia) converted, and made Malacca a center of Muslim-derived trade and learning. This helped Islam grow not only in Malacca, but the rest of Sumatra, Java, and places like Borneo and even the Southwest Philippines (Mindanao). Later, the religion spread to other parts of modern Indonesia when it assimilated some Bhuddist and Hindu rituals, along with their followings in the country.

The dynamics of the Muslim religion are different in Indonesia than elsewhere. Because of its association with "traders," the so-called "modernist" school is dominant in Indonesia. That is to say that the religion was associated with the most socially advanced, economically "progressive" elements of society. This is in contrast to the desert kingdoms of e.g., the Middle East, where it is embraced by the most traditional elements of society. As a result, the Indonesian version of the Muslim religion is more tolerant and less severe than elsewhere.

  • You do not mention that they converted to Islam to gain support from Muslim rulers in India and elsewhere, and for support from Zheng He, to gain support to be independent from the Mahajapit empire.
    – user44626
    Commented Jun 4, 2020 at 17:21

Maritime networks shifted Mahajapit vassals to Islam, moving it away from the Hindu-Buddhist faith. Islam had an advantage over other religions, because it was founded by merchants! Converting places to Islam only required books, while converting places to Hinduism required temples, which were much costlier. So in the 13th century, many locals in Indonesia began converting to Islam. Why? Well, we know that many Mahajapit vassals and enemies may have wanted some level of secure autonomy. This meant that those kingdoms would look to foriegn powers fro security. Before this, they would either look to Hindu India or Buddhist China for help. This is why Indonesia used to be Hindu-Buddhist. But in the 13th century, Islam was accepted in China under the Mongols. Islam also brought advanced Arabic writing, paper, and, most importantly, good relations with Muslim powers in India. This meant that the vast knowledge from the science of Hinduism and Buddhism could be translated to Arabic, and combined with the science from the Arabic World. And even more importantly, nations that wanted autonomy from the Mahajapit empire looked to Indo-Muslim powers or China, where the Mongols allowed Muslims to live. Later on, Zheng He was one of the main Chinese explorers who went on diplomatic missions into Southeast Asia. He was Muslim as well. So now the options for most kingdoms in Southeast Asia were this: Either stay as part of the Mahajapit empire(which was in a civil war), Declare themselves not loyal to the Mahajapit rule and then get crushed by Mahajapit navies, or convert to Islam, gain the favor of INDIA AND CHINA, learn Arabic knowledge, and then declare yourself independent. The Mahajapit empire can't do anything because you have two strong powers on your side.

In addition, Ibn Battuta was in Indonesia, and that helped Islam to spread into Indonesia.

Anyway, the year was 1398. The great Mahajapit empire was very strong and it indirectly controlled much of Indonesia. It sent ships to conquer the weaker kingdom of Singapore. Why? Because Singapore was the last bit of their old, strong rival Srivijaya. All the last remains of Srivijaya were taken to Singapore. Singapore is one of the example cities for converting to Islam. They had the expansionist Thai kingdom to the north to worry about as well. So while Singapore was being invaded, the king of Singapore (Srivijaya) fled to a strategic location. He converted to Islam, to gain support of India and Zheng He, and collected taxes from traders. He was right on the Strait of Malacca so he was prime to get rich from trade. He called his new empire the "Sultanate of Malacca". After getting a secure relation with China and India, he started to spread his influence through Indonesia.

The deal between China and the Sultanate of Malacca was this: China would get a check on Thai and Mahajapit power, and Malacca would get a strong navy and be secure. The deal between India and other Muslim powers and the Sultanate of Malacca was this: Convert to Islam, and I'll make sure I buy from you, paying taxes when I trade. Like this, many kingdoms freed thenselves of Mahajapit rule and converted to Islam. Mahajapit power began falling, and on top of that, the civil war hurt Mahajapit even more. Mahajapit was the last Hindu-Buddhist kingdom in Indonesia. They began losing money as the trade in Indonesia was shifting to Muslim powers. Eventually, Sumatra rebelled, and all Mahajapit controlled now were Java, Bali, the Spice Islands, and various small islands. However, eventually, Java itself was captured by a coalition of various Muslim kings. Now, Mahajapit was basically dead, as the Spice Islands had changed sides. Then, Mahajapit surrendered, but gave their culture to Bali. Bali continued to be a Hindu-Buddhist Island to this day, and still preserves old Mahajapit culture. Mahajapit theatre was one of the greatest forms of art, and Mahajapit history eventually became the spark that created the fire of Nationalism in Indonesia, which stopped the imperial Dutch rule centuries later. None of the previous answers really satisfy the question. The reason is clear: Bali is the last stronghold of Mahajapit culture after the rest of the Mahajapit empire converted to Islam, to get protected from Mahajapit by India and China.

Check out Extra Credits' video on this topic. You should also look at his previous videos for information on the Mahajapit Empire. You should also check out this histomap of the Mahajapit empire.

Hope this answers your question.


In high school in the US, we generally learned that until Europeans started sailing the world, with Vasco Da Gama and Christopher Columbus, there was no long distance sailing. The impression I got was that Europeans were the first to figure out how to explore, and how to trade, and how to sail. This is not correct; many traders vied the seas for centuries before the "Age of Exploration".

In relation to your question, the Indian Ocean Trade Routes began millenia before the European expansion. It certainly preceded the existence of Christianity and Islam. This is how Hinduism arrived in Indonesia - through trade with the seafaring Hindu regions.

There have been finds of Roman coins in Kerala, as well as Chinese coins from the Tang Dynasty. The proximity of Kerala to the Middle East, and the presence of Tang Dynasty coins in Kerala from the time of rapid Muslim expansion provides us a clue of how Islam spread to Indonesia. Please note that the Tang Dynasty (618 - 907) and the Muslim expansion (622 - 750) occurred at the same time.

It is also notable that Kerala has a large Muslim population as well as an ancient (apostolic?) Christian population. The Kerala christians are so ancient that it is said that one of Christ's apostles, St Thomas, founded their church.

I have photos from a museum in Fujian where they show architectural art from Christian, Muslim, Jain, and Hindu temples that were established by merchant communities. ( Posted at the end of this answer1) They often show a blending of Chinese, Indian, and Middle Eastern art. The contents of the museum were dated to about 700 C.E.; from when the Tang dynasty was very cosmopolitan and before the persecutions by Tang Emperor Wuzong. There was also a tremendous mixing of peoples in China during 618 - 845; many of which arrived by sea in Quanzhou, a famous ancient port city in SE China.

So, How did Islam arrive in Indonesia?

I think Tom Au's answer gives a nice set of details. The thrust of my answer is more general; my point is that considering the level of trade and mixing of peoples during this era through the Indian Ocean, it should not be at all surprising that Islam is in Indonesia, SE Asia, and China.

Specifically, The middle east traded with Kerala, and Kerala and Tamil traders passed Indonesia on the way to China. As this whole area was well civilized at this time, the spread of a civilized religion is not at all surprising.

Some photos I took at a museum in Quanzhuo, China of some artifacts that were dated as about 700 c.e.: Ancient Chinese Christian Tombstone From Quanzhou China Ancient Chinese Christian Tombstone From Quanzhou China Ancient Chinese Christian Tombstone From Quanzhou China Ancient Chinese Christian Tombstone From Quanzhou China

  • Your are missing the people from Borneo who settled in Madagascar some 1500-2000 years ago.
    – JRB
    Commented Apr 9, 2019 at 21:49
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    @JRB How does that help explain how Islam came to Indonesia? (Thanks for reminding me to come and post these photos) Commented Apr 9, 2019 at 22:46
  • This was in pre-islam times, but I was amazed to learn about it. It illustrates that a lot of seafaring went on in ancient times by non-western peoples
    – JRB
    Commented Apr 10, 2019 at 7:59
  • @JRB Please check out some other questions related to this, including recent Why was Madagascar settled by far-flung Austronesian seafarers? and another one Why Were Madagascar and New Zealand Discovered So Late? and of course some more Commented Apr 10, 2019 at 10:46
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    The statement "began millenia before the European expansion" is simply incorrect. The earliest evidence is from the third century B.C.E., roughly 1200 years before the European expansion (from your own link). That's only a bit more than a single millenium. Commented Jun 5, 2020 at 4:27

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