Which ruler made budhism an international religion?

Asoka the Great- Asoka, the first Buddhist Emperor, was the ruler of the Magadhan empire. Initially a ruler obsessed with the aim of expanding his empire, he changed after witnessing the brutal carnage at the battle of Kalinga. This event led him towards Buddhism and he built his empire into a Buddhist state, a first of its kind. He laid the foundation of numerous stupas and spread the teachings of Lord Buddha throughout the world.