After the demise of Almarhum Sultan Mahmud Iskandar Shah in 1720, Raja Radin* who was the prince of Almarhum Yang di-Pertuan Muda Raja Mansur (Marhum Mangkat di Pulau Tiga) was installed as Sultan with the title Sultan Alauddin Mughayat Shah. He resided at Geronggong, whilst his younger brother, Raja Inu, resided at Bernam and was made the Raja Muda.
[*Raja Mansur was the brother of the long-reigning Almarhum Sultan Mahmud, and as Almarhum had no issue, his nephew Raja Radin ibni Raja Mansur was installed as Sultan.]
Sultan Alauddin Mughayat Shah mangkat in 1728 and was conferred the title Marhum Sulong. He was interred in Geronggong at Kampung Jawa, Pulau Tiga, Daerah Kecil, Kampung Gajah, together with the makam of his uncle, Marhum Besar Aulia Allah Sultan Mahmud.