Occurring in a relatively naturalistic form in the earliest monuments, notably the great stupa at Sanchi (c. 50 BC) and in the Kushan (Kushān art) sculpture of Mathura (1st–3rd century AD), the vyala assumed a definite stylized form about the 5th century. From the 8th century onward, it was constantly employed in architectural decoration, being repeated, for example, on the walls of temples.