The investiture of Ardashir I who ruled from 226-242 CE is a Sassanid rock relief at Naqsh-e-Rostum. The founder of the Sassanid empire is seen being handed the ring of kingship by Ahura Mazda . The accompanying bilingual inscription bears the oldest attested use of the term Iran and the king calls himself “Ardashir, king of kings of the Iranians”.