Bruneian–Tundun War

The Bruneian–Tundun War, also called the Bruneian Expedition to Luzon and the Bruneian invasion of Tondo, was a military invasion and later occupation of Tondo in Luzon by the Bruneian Sultanate in the 15th century. The invasion resulted in the formation of the Kingdom of Selurong, the Brunei Sultanate chose to end the Dynasty of Tondo's monopoly in the China trade.

Background
In c. 1500, prior to the Spanish reached in the Philippines, the Bruneian Empire, launched an attack on the Kingdom of Tondo, a significant trading city located on Luzon Island. Bolkiah, the fifth Sultan who controlled the Sultanate from 1485 to 1525, was in charge of the Bruneian Empire at the time of the assault. Given that Bolkiah supervised Brunei's rise to prominence as a powerhouse that swept over the Malay Archipelago, his reign is perhaps best remembered as the empire's golden period. The first records of a Maynila and a Tondo date back to the Martín de Goiti voyage to Manila in 1570.

Battle
Sultan Bolkiah was renowned for frequently traveling overseas in an effort to get fresh perspectives and information that would aid in the development of his nation. But he really started to gather traction in 1500 when he made the decision to visit the Kingdom of Tondo in an effort to increase his power. Bolkiah founded the city of Selurong—later named Maynila, on the other side of the Pasig River shortly after taking over Tondo from its monarch, Lakan Gambang.

Following the Sultan's victory in Tondo, the customary Rajahs, referred to as the Lakandula, kept their titles and possessions, but the House of Soliman, which housed the Manila Rajahs, gained control of them. Following this triumph, Brunei ruled over Borneo and the western Philippines for almost a millennium, until starting to decline in influence in the 18th century.

Aftermath
As a result of this victory, Brunei had control over Borneo and the civilisations around the Manila Bay, it only truly begin to lose its holdings in the 1700s. Through Brunei, Tondo was connected to the international commercial network centered at Melaka. It wasn't until Bruneian traders moved in the Manila region at the beginning of the 16th century that Luzon started to become Islamic. Islam had spread as far north as Luzon by the time the Spanish came, and Rajah Sulaiman II governed Manila.