Brut y Tywysogion (English: Chronicle of the Princes) is one of the most important primary sources for Welsh history. It is an annalistic chronicle that serves as a continuation of Geoffrey of Monmouth’s Historia Regum Britanniae. Brut y Tywysogion has survived as several Welsh translations of an original Latin version, which has not itself survived. The most important versions are the one in Robert Vaughan's Peniarth MS. 20 and the slightly less complete one in the Red Book of Hergest. The version entitled Brenhinoedd y Saeson (Kings of the English) combines material from the Welsh annals with material from an English source.