This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Muslim Malay and Arab merchants had long traded through the Southeast Asian archipelago when the Sunni scholar Shaykh Makhdum Karim reached the Sulu Archipelago and the island of Jolo in 1380 and began establishing Islam through the trade contacts he built across several islands. A decade later, in 1390, the Minangkabau prince Rajah Baguinda arrived with his own followers to continue the same missionary work Shaykh Makhdum Karim had begun.
Yemeni, Chinese Muslim, Indian Muslim and Persian traders, together with further Sufi missionaries, all contributed to the tradition's growth across the archipelago over the following century, building on the foundation the two earlier arrivals had laid rather than starting the process themselves. That century of combined trade and missionary activity established the Sultanate of Sulu and, with it, Islam's enduring presence in the southern Philippines.
What this changed for Islam's spread was the tradition's arrival in the southern Philippines through a specific sequence, a scholar's missionary landing at Jolo in 1380 followed a decade later by a prince's own following, rather than through a single conversion event. The Sultanate of Sulu that grew from this century of activity gave Islam a lasting institutional home in the archipelago that has endured since.