The first clear mention of a navy occurs in the mythological epic Mahabharata. Historically, however, the first attested attempt to organise a navy in India, as described by Megasthenes (c. 350—290 BCE), is attributed to Chandragupta Maurya (reign 322—298 BCE). The Mauryan empire (322-185 BCE) navy continued till the times of emperor Ashoka (reign 273—32 BCE), who used it to send massive diplomatic missions to Greece, Syria, Egypt, Cyrene, Macedonia and Epirus. Following nomadic interference in Siberia—one of the sources for India's bullion—India diverted its attention to the Malay peninsula, which became its new source for gold and was soon exposed to the world via a series of maritime trade routes. The period under the Mauryan empire also witnessed various other regions of the world engage increasingly in the Indian Ocean maritime voyages.