This site may help you: http://www.rasta-man.co.uk/religion.htm

"Rasta, or the Rastafari movement, is a cultural value system that accepts Haile Selassie I, the former Emperor of Ethiopia, as God incarnate, whom they call Jah. He is also seen as part of the Holy Trinity as the messiah promised in the Bible to return. The name Rastafari comes from Ras (literally "Head," an Ethiopian title equivalent to Duke), and Tafari Makonnen, the pre-coronation name of Haile Selassie I. The movement emerged in Jamaica among working-class and peasant black people in the early 1930s, arising from an interpretation of Biblical prophecy partly based on Selassie's status as the only African monarch of a fully independent state, and his titles of King of Kings, Lord of Lords, and Conquering Lion of Judah (Revelation 5:5). Other characteristics of Rastafari include the spiritual use of cannabis, and various Afrocentric social and political aspirations, such as the teachings of Jamaican publicist, organiser, and black separatist Marcus Garvey (also often regarded as a prophet), whose political and cultural vision helped inspire a new world view. The Rastafari movement has spread throughout much of the world, largely through interest generated by reggae music—most notably, that of Jamaican singer/songwriter Bob Marley. By 2000, there were more than one million Rastafari faithful worldwide. About five to ten percent of Jamaicans identify themselves as Rastafari. Many Rastafari follow an ital diet which essentially means living by the dietary Laws of Leviticus and Deuteronomy in the Old Testament." Source and further information: http://en.wikipedia.org/wiki/Rastafarian