St Gregor'y Homilies on the Gospel were delivered during the first year of his pontificate. They have come down to us in the revised form which he gave them in 593. A critical edition is still awaited and it would be wise not to attach too much importance to the topographical stational indications which appear in the printed editions. Not all manuscripts give these stational headings, nor is there complete harmony among those that have such indications. From internal evidence it would appear that St Gregory preached the present Homily during the Advent of 590. In it he alludes to the unprecedented tempests which had afflicted Rome during the November of 589, to the decimation of the population by the consequent plague, to the collapse of buildings and churches. All these details are corroborated by the words of Agiulf, deacon of St Gregory of Tours, who was an eye-wintness of the events: ‘In the preceding year’ (589), he writes, in the ninth month, the River Tiber so flooded the City of Rome that ancient buildings were washed away, and the Church's granaries were submerged.’ (cf.Hist. Franc. x, 1.) Much of the final passages of this homily is resumed in almost identical terms in the collect for the Vigil of Christinas.