 In 1539, Aru, Johor's vassal state on the east coast of Sumatra, was attacked by a fleet of 160 ships with 12,000 soldiers, being Acehnese, Malaccan Malays, Malabaris, Gujaratis, and Turkish.Alauddin Riayat gathered a fleet with aid from his allies, Perak and Siak, and attacked Aru in 1540.He reconquered Aru, leaving only 14 Acehnese ships afloat and thousands of Acehnese troops dead.