On March 26, 1873, the Dutch warship Citadel van Antwerpen opened fire on the coast of Aceh. Thousands of troops from the Dutch East Indies army were deployed to capture the palace of Sultan Mahmud Syah in Kutaraja.
The assault marked the beginning of a war that would last for decades and become one of the longest colonial conflicts in the history of the Indonesian archipelago.
Yet the roots of the war lay deeper than disputes over trade or piracy in the Strait of Malacca. Long before the first cannon was fired, Aceh had already sent envoys to Istanbul and held negotiations with the United States consul in Singapore.
These diplomatic efforts were later used by the Dutch as a justification for invasion. They also relied on a treaty signed in The Hague two years earlier without Aceh's knowledge or participation.
A Treaty Signed Without Aceh
On November 2, 1871, Britain and the Netherlands signed the Sumatra Treaty in The Hague. Article I of the treaty stated unequivocally:
"Her Britannic Majesty desists from all objections against the extension of the Netherland Dominion in any part of the island of Sumatra."
With this provision, Britain formally withdrew all objections to Dutch expansion anywhere on the island of Sumatra, including Aceh, which had previously remained outside direct Dutch control.
The treaty was not a standalone agreement. It formed part of a broader colonial exchange between the two powers. The Netherlands ceded all of its possessions on the Gold Coast in West Africa to Britain. In return, Britain granted the Dutch a free hand to expand their authority across Sumatra.
Aceh itself, despite being the territory whose future was effectively decided by the treaty, was neither consulted nor informed during the negotiations.
Aceh Sought Allies in Istanbul and Singapore
According to research by Nia Deliana published in İnsan ve Toplum Dergisi: The Journal of Humanity and Society which draws extensively on the classic works of historian Anthony Reid, Aceh did not remain passive.
The sultanate had already established ties with the Ottoman Empire years earlier. In 1852, Sultan Ibrahim Mansur Syah sent an envoy to Istanbul to request the renewal of Aceh's former vassal status under the Ottoman Empire. The delegation returned with honorary gifts from the Ottoman Sultan.
Two decades later, in 1872, Aceh dispatched another mission to Istanbul. This time, it was led by Habib Abdurrahman al-Zahir. The delegation asked the Ottoman Empire to formally restore its protective relationship with Aceh.
The request sparked intense debate among Ottoman elites. It also received widespread press coverage, including in the Istanbul newspapers al-Jawa'ib and Basiret, as well as in Western publications such as the Pall Mall and The New York Times.
Aceh did not stop there. In early 1873, its representatives also opened negotiations with the United States consul in Singapore to discuss the possibility of a treaty of friendship.
Acehnese envoys were also reported to have approached the British and Danish consulates in Singapore. Contemporary reports further suggested that they made contact with the Italian, French, and Siamese consulates.
The Pretext the Dutch Had Been Waiting For
News of Aceh's diplomatic outreach to several foreign powers soon reached the Dutch authorities. They viewed these efforts as a direct challenge to the exclusive authority they had just secured under the 1871 Sumatra Treaty.
For the Dutch, Aceh's attempt to seek foreign protection provided the justification they needed to move beyond territorial claims on paper and launch a military campaign.
The first Dutch expedition, launched in March 1873, ended in a humiliating defeat. The expedition's commander, Major General J.H.R. Köhler, was killed in battle, and Dutch forces were forced to retreat.
Rather than ending the conflict, the failed invasion strengthened Acehnese resistance. The resistance became increasingly organized, supported in part by a network of Acehnese leaders based in Penang. British officials referred to this network as the Council of Eight.
Throughout the following years, it continued seeking support from various foreign consulates until the Dutch launched a second expedition in 1874, which succeeded in capturing the royal palace at Kutaraja.
Sultan Mahmud Syah died of cholera in 1874, shortly after the fall of his palace. He was succeeded by an heir who was only 11 years old.
Even so, Aceh's resistance did not end. The war, which officially began with a single cannon shot in 1873, continued for decades. It outlasted the tenures of both the Dutch commanders and the Acehnese sultans who had been involved at the outbreak of the conflict.
