When he became pope Italy was in a state of crisis, devastated by floods, famine, and Lombard invasions, and the position of the Church was threatened by the imperial power at Constantinople; it was owing to Gregory that many of these problems were overcome. He made a separate peace with the Lombards in 592–93, and (acting independently of the imperial authorities) appointed governors to the Italian cities, thus establishing the temporal power of the papacy. One of his greatest achievements was the conversion of England to Christianity, by St Augustine of Canterbury. Throughout his papacy he effectively opposed the double assault on the Church from paganism and the Arian heresy. His interest in music led to developments in the plain chant which bears his name—the Gregorian Chant.