Today we commemorate Gregory the Great, Pastor. Gregory served both as mayor and, later, as bishop of Rome. Before entering full-time service in the Church, Gregory helped to strengthen a Rome weakened by enemy invasions and plague, and sold his considerable possessions and donated the proceeds to help the poor. As bishop of Rome, Gregory contributed to the Church by establishing a Church Year calendar, which some church bodies still use to this day, and overseeing musical and liturgical development, advancing missionary work in Northern Europe, and composing a book on pastoral care that would long serve as a standard in the Church.