The Mauryan art is believed to be inspired from Achaemenid or Persian influence. We can find a lot of similarities in terms of form and style in the inscriptions of Ashoka and the Persian king Darius.
According to the Rabatak inscription, Kujula Kadphises was the great grandfather of the great Kushan king Kanishka I. He is considered as the founder of the Kushan Empire. He died in the year 80 A.D.