Buddhism in the West broadly encompasses the knowledge and practice of Buddhism outside of Asia. Occasional intersections between Western civilization and the Buddhist world have been occurring for thousands of years. With the rise of European colonization of Buddhist countries in Asia during the 19th century detailed knowledge of Buddhism became available to large numbers of people in the West, as a result of accompanying scholarly endeavours.
The Western and Buddhist worlds have occasionally intersected since the distant past. It was possible that the earliest encounter was in 334 BCE, early in the history of Buddhism, when Alexander the Great conquered most of Central Asia. The Seleucids and successive kingdoms established Hellenistic influence in the area, interacting with Buddhism introduced from India, producing Greco-Buddhism.
The Mauryan Emperor Aśoka (273–232 BCE) converted to Buddhism after his bloody conquest of the territory of Kalinga (modern Orissa) in eastern India during the Kalinga War. Regretting the horrors brought about by the conflict, the Emperor decided to renounce violence. He propagated the faith by building stupas and pillars urging, amongst other things, respect of all animal life and enjoining people to follow the Dharma.
Perhaps the finest example of these is the Great Stupa of Sanchi in India. This stupa was constructed in the 3rd century BCE and later enlarged. Its carved gates, called Toran, are considered among the finest examples of Buddhist art in India. He also built roads, hospitals, universities and irrigation systems around the country. He treated his subjects as equals regardless of their religion, politics or caste.
This period marks the first spread of Buddhism beyond India to other countries. According to the plates and pillars left by Aśoka (the edicts of Aśoka), emissaries were sent to various countries in order to spread Buddhism, as far south as Sri Lanka and as far west as the Greek kingdoms, in particular the neighboring Greco-Bactrian Kingdom, and possibly even farther to the Mediterranean.