 Theories of the Church’s pre-Carolingian beginning are supported by the Chronicon Sancti Martini Coloniensis, which up until the end of the 19th century was regarded as a valid historical source for Churches and Abbeys in Cologne.According to it, Great St. Martin was founded as a chapel in 690, and was transformed into a monastery by Viro, Plechelmus and Otger in 708.The Chronicon provides an unbroken history of the abbey and the events leading to its partial destruction by Saxons in 778, while Charlemagne was fighting in Spain.