As the first base of European Christian trading kingdom in Southeast Asia, it was surrounded by numerous emerging native Muslim states. Also, with hostile initial contact with the local Malay policy, Portuguese Malacca faced severe hostility. They endured years of battles started by Malay sultans who wanted to get rid of the Portuguese and reclaim their land. The Sultan made several attempts to retake the capital. He rallied the support from his ally the Sultanate of Demak in Java who, in 1511, agreed to send naval forces to assist. Led by Pati Unus, the Sultan of Demak, the combined Malay–Java efforts failed and were fruitless. The Portuguese retaliated and forced the sultan to flee to Pahang. Later, the sultan sailed to Bintan Island and established a new capital there. With a base established, the sultan rallied the disarrayed Malay forces and organized several attacks and blockades against the Portuguese's position. Frequent raids on Malacca caused the Portuguese severe hardship. In 1521 the second Demak campaign to assist the Malay Sultan to retake Malacca was launched, however once again failed with the cost of the Demak Sultan's life. He was later remembered as "Pangeran Sabrang Lor" or "the Prince who crossed (the Java Sea) to North (Malay Peninsula"). The raids helped convince the Portuguese that the exiled sultan's forces must be silenced. A number of attempts were made to suppress the Malay forces, but it wasn't until 1526 that the Portuguese finally razed Bintan to the ground. The sultan then retreated to Kampar in Riau, Sumatra where he died two years later. He left behind two sons named Muzaffar Shah and Alauddin Riayat Shah II.