Rastafari is an Abrahamic religion that developed in 1930s Jamaica. The name comes from "Ras", the Ethiopian word for chief or prince, and Tafari (the revered one) which was the first name (before his coronation) of Emperor Haile Selassie, who ruled Ethiopia in 1930 through 1974. Rastafari worship Haile Selassi as the incarnation of God the Father (Jah, a shortened form of the biblical name of God) and is Christ in his second coming. Today is a Rastafari holiday because it is the emperor's birthday in 1892. This BBC site provides information about this faith, as does this site.