There were both economic, political and religious reasons for the intense rivalry. At stake was the control of the trade through the Melaka Straits. In 1547, Alauddin personally participated in a night attack on Melaka. However, the Acehnese fleet was defeated at the Perlis River. After the failure, Aceh returned to a comparatively peaceful state for 15 years. However, in 1564 he led a fleet of ships, ostensibly to go to Patani. Suddenly, he ordered the course changed and instead assaulted Johor, the successor state of the old Melaka Sultanate. The enterprise was successful; Johor was sacked and Alauddin brought its sultan, Alauddin Riayat Shah II of Johor, to Aceh where he had him killed. A Johor princess was married to the sultan. Instead of the deposed ruler, Muzaffar II was placed on the throne of Johor. With the defeat of Johor, Aru fell to Aceh and was entrusted to Alauddin's son Abdullah. In January 1568 the sultan undertook another attack on Malacca. He personally led 15,000 troops and 400 Ottoman elite soldiers, using 200 bronze cannons. The Portuguese, surprised by the assault, applied for help from the Malay neighbours of Johor and Kedah. They were nevertheless able to beat back the Acehnese before the Malay allies had even arrived. At this occasion, Alauddin's oldest son Abdullah of Aru was killed. The attitude of Johor enraged the sultan who burned many Johorese villages on his way back to Aceh. When Muzaffar of Johor was poisoned, Alauddin sent another fleet to Johor, but had to return due to the strength of Johor's defenses. The Turkish connection In order to strengthen his case, Alauddin dispatched envoys to the Ottoman sultan Suleiman the Magnificent in about 1561–1562, asking for assistance against the infidel Portuguese. At this time the predatory practices of Portuguese ships made the sea route over the Indian Ocean dangerous for Muslim ships. An alternative route for pepper trade therefore developed from about 1530, where Gujarati, Arab, Turkish and Acehnese traders brought spices directly from Aceh to the Red Sea without coming near Portuguese strongholds in the Melaka Straits. The Ottomans and Aceh thus had common interests to counter the Portuguese might on the oceans. Turkish gunners were sent to Aceh by 1564. The next Ottoman sultan, Selim II, showed enthusiasm for supporting the Acehnese. He equipped a fleet of 15 galleys and two barques. However, before it could be dispatched,