The invasion of Alexander and the westward spread of Buddhism brought India into contact with Persia, where the Achaemenian kings had hewn out mausolea in the rocks, and built palaces with stone basements, doorways and pillars, filling in the walls with bricks. These works would attract the attention of Indian visitors--ambassadors, missionaries and merchants; and the report of such magnificent works would lead to their imitation. About the middle of the 3rd century B.C. we find the great Asoka, the grandson of Chandragupta, in communication with the contemporary kings of Syria, Egypt, Macedonia, Epirus and Cyrene; and to his reign belong the great stone pillars, with capitals of Persian type, that are engraved with his religious edicts. A convert to Buddhism, Asoka is credited with the construction all over the country of vast numbers of stupas--monumental structures enshrining relics of Sakyamuni Buddha or other Buddhist saints; and with them were erected monasteries and chapels for the monks. On the monumental pillars, known as lats, set up by this emperor, besides the Persepolitan form of capital, we find the honeysuckle with the bead and reel and the cable ornaments that were employed in earlier Persian carvings; and though not continued later in India proper, these prevailed in use in Afghanistan for some centuries after the Christian era. This seems to indicate that these forms first came from Persia along with the ideas that led to the change of wooden architecture for that of stone. The stupas were structures that may be regarded as conventional architectural substitutes for funeral tumuli, and were constructed to enshrine relics of Buddha or of his more notable disciples, or even to mark the scene of notable events in the tradition of his life. How relic-worship originated and came to hold so large a place in the Buddhist cult we can hardly conjecture: the sentiment could not have arisen for the first time on the death of Gotama Buddha, when, we are told, eight stupas were built over his corporeal relics, a ninth over the vessel with which they were divided, and a tenth over the charcoal of the funeral pile.