from the time of st. ambrose, whose hymns are well-known and whose liturgical allusions may certainly be explained as referring to a rite which possessed the characteristics of that which is called by his name, until the period of charlemagne (circ ad 800), there is a gap in the history of the milanese rite. however, st. simplician, the successor of st. ambrose, added much to the rite and st. lazarus (438-451) introduced the three days of the litanies. ("cantù, milano e il suo territorio", i, 116) the church of milan underwent various vicissitudes and for a period of some eighty years (570-649), during the lombard conquests, the see was moved to genoa in liguria.