The word "REGGAE's" beginning is unknown.

First the word "REGGAE" was mentioned in "Do the Reggae" (1968) by Toots and the Maytals.
In 1968 the song "The Israelites" (by Desmond Dekke) became the
first song of Reggae which took the first places in German and
British charts. Bob Marley, Jamaican musician and national hero, interconnected "Reggae" wich "Rastafarai".