From Iranun and Balangingi: Globalization, Maritime Raiding and the Birth of Ethnicity, by James Francis Warren (Singapore U. Press, 2002), pp. 53-56:
The Iranun burst quite suddenly into Southeast Asian history in the second half of the eighteenth century with a series of terrifying raids and attacks on the coasts and shipping of the Philippines, the straits of Malacca and the islands beyond Sulawesi. Their primary targets were unprotected coastal settlements and sailing boats that travelled throughout Southeast Asia bringing valuable commodities from China and the West back to the most remote parts of the archipelago. Many of these marauders were sponsored by rulers from the trading states of Cotabato, Sulu, Siak, and Sambas. They were soon described as ‘Lanun’ or ‘Illanoon’—‘pirates’—by those who suffered their depradations or either travelled with or hunted them and wrote about their widespread impact on the Southeast Asian world.
It is estimated that during the last quarter of this century (1774–1798) of maritime raiding and conflict against the Dutch and Spanish, between 100 and 200 seaworthy raiding prahus set out from the Mindanao-Sulu area each year. The sheer size of the vessels—the largest joanga measuring upward of 130 feet in length—and the scale of the expeditions dwarfed most previous efforts, marking a significant departure in the naval strategy of Malay maritime raiding as it had been traditionally understood. The Iranun were far more than mere ‘pirates’ or brigands. The colonial powers and precolonial Malay trading states had to reckon with a dominant force in their own right; a force that was capable of inflicting major defeats on the Spanish and Dutch and toppling local kingdoms. The huge numbers of these skilled sea raiders and slavers that the sultanate of Sulu could mobilize during the heyday of the China trade would henceforth have a profound impact upon Southeast Asia’s history.
The geographical range of Iranun-Balangingi slave raiding activity was enormous, spanning all of Southeast Asia and beyond. Until the latter part of the eighteenth century, the joanga of the Cotabato and Sulu Sultanates were more or less integrated into fleets belonging to the respective sultanates, but by the end of the century many Iranun vessels were also operating independently. Iranun prahus sponsored by both states had their own target areas but inevitably, there was some overlap. Cotabato and Sulu raiding vessels cruised between the Visayas and Luzon, and out into the South China Sea. Those from Tempasuk, on the northwest coast of Borneo, harassed shipping to the west of the huge island itself. Samal Balangingi, situated midway between the Iranun communities in Mindanao and those on Borneo, operated vessels throughout the Philippines and in the central and eastern parts of the Netherlands Indies.
Iranun maritime raids affected virtually the entire coastline of Southeast Asia, and even stretches of New Guinea and the Bay of Bengal were not secure from slave raids. In the east, the Iranun sailed down the Makassar Strait to cross the Java Sea and South China Sea to attack the north coast ports on Java and the large tin mining island of Banka. Iranun raided extensively in the Sangir Islands, Halmahera and, to a lesser extent, in the Moluccas. They also pushed beyond the defended limits of the Southeast Asian world, crossing the South China Sea to attack undefended stretches of the coastlines of Thailand and Cochin China. At the opposite extremity they also raided, but failed to dominate, the dangerous coasts of New Guinea. In the 1790s, Iranun slave hunters in search of captives extended the limits of their known world even further, sailing far into the waters of the Bay of Bengal, touching at the Andaman Islands and perhaps exploring the southern coast of Burma. There seemed no practical way for the colonial powers to link their respective ‘dominions’ together in an island-wide network of defense and communication, and consequently the Iranun made the most of the ill-defended seas and ravaged the coastal populations and commerce….
In the second half of the eighteenth century many Philippine ports, towns, shipyards, and monasteries were not adequately defended while others were totally defenseless. From the mid-1750s onward, the scale, ferocity and unexpected nature of the initial wave of Iranun attacks were deeply disturbing. Thousands of Filipinos perished or were seized as captives; the more so as the Iranun were Muslims and recognized none of the accepted conventions and taboos that were meant to protect the property and personnel of the Catholic Church in times of war between Christians…. This terrifying period of Iranun slave raiding activity, which lasted more than 70 years from roughly 1752 to 1832, severely hampered the overall social and material well-being and growth of the Philippine island world and the colonial state.