Alauddin Riayat Shah II of Johor

Sultan Alauddin Riayat Shah II ibni Almarhum Sultan Mahmud Shah (died 1564) was the first sultan of Johor. He ruled Johor from 1528 to 1564. He founded the Johor Sultanate following the fall of Malacca to the Portuguese in 1511. He was the second son of Mahmud Shah of Malacca. Thus, Johor was a successor state of Malacca and Johor's sultans follow the numbering system of Malacca. Throughout his reign, he faced constant threats from the Portuguese as well as the emerging Aceh Sultanate.^{[citation needed]}