Gesar (Tibetan, Ge-sar). A mythical hero king whose wondrous exploits inspired the Epic of Gesar which achieved great popularity in Tibet and Mongolia. The events of Gesar's life probably draw on many different central Asian sources and traditions, and the name ‘Gesar’ itself is thought to derive ultimately from the title ‘caesar’. The epic comprises several cycles of stories and is composed in verse and prose. It was formerly handed down by an oral bardic tradition though now the diverse oral traditions have been largely collected together in written form.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)