One of his inscriptions mentions that he ruled over a thousand islands, and this perhaps could be Lakshadweep. According to some scholars, Rajasimha provided some military assistance to the emperor of China who fought with the Arabs at that point of time. Named after his great-grandfather, Narasimhavarman I (Mamalla), he shared his ancestor's fervor for temple architecture. He initiated the concept of constructing structural temples out of stone. One among these was the famous Shore Temple at Mamallapuram and another Talagirishwara temple at Panamalai (near Viluppuram). But the grandest was the Kailasa-natha temple at Kanchipuram, built of sandstone.
Rajasimha Pallava's court at Kanchi sheltered several scholars and is well known from the works of Dandin, the famous Sanskrit scholar that he was honoured at Rajasimha's assembly.