Raja Bisnu was the prince of Yang di-Pertuan Muda Mansur Shah (Marhum Mangkat di PulauTiga) and the younger brother of Sultan Mudzaffar Shah III (Raja Inu). During Sultan Mudzaffar III’s reign, Raja Bisnu was made Yang di-Pertuan Muda or Sultan Muda with the name Yang di-Pertuan Muda Muhammad Shah, and resided in Pulau Tiga. As described in an earlier SembangKuala post, the brothers came into conflict in 1742-3, causing turmoil in Perak, dividing the state into two, during which the Yang di-Pertuan Muda Muhammad Shah was made Sultan Muhammad Shah. During this time, he made his son, Raja Iskandar, his eldest son as Raja Muda and left the administration of his half of Perak (from Pachat to Hilir Perak) to the Raja Muda. Raja Muda Iskandar was said to be a wise and fair ruler and administrator. However, Sultan Muhammad Shah’s reign was shortlived as both the warring brothers finally reconciled, leaving Sultan Mudzaffar Shah III as the sole ruler of Perak.
However, Yang di-Pertuan Muda Muhammad Shah mangkat before his elder brother, Sultan Mudzaffar Shah III, in 1750. He was interred next to the makam of Almarhum Sultan Mahmud Shah, the eighth Sultan of Perak, in Pualu Tiga and was conferred the title Marhum Aminullah.