This study explores the regional specificity of Buryat rites with regard to the variable manifestation of mythological and historical components, and late innovations. The first attempt is made to reconstruct the mythological component of spoken texts accompanying these rites in the historical and ethno-cultural context. On the basis of field and archival data, contamination and transformation of myth and history in ritual is demonstrated. The principal characters such as deities, shamans, tribal and clan chiefs are described, and the semantics and pragmatics of ancestor and master- spirits in the historical context are discussed. The mythological status of supernatural characters of the rite is assessed. Specific ethnic criteria of turning real personalities into mythological characters in the historic context are listed. Universal features traceable in the process of turning history into myth include a regular mixture of mythological motifs with historical facts, interchange of temporal planes, and especially the reincarnation theme. The conclusion is made that pragmatic rites are the most stable, whereas the general tendency is that rites become less and less connected with mythology and progressively less hyperbolic.