After the sack of Rome in 410, communications and travel between east and west deteriorated. Liturgical developments in Rome and Constantinople did not always match, although a rigid adherence to form was never mandated in the church. Nevertheless, the principal points of development were maintained between east and west. The Roman and Constantinopolitan liturgical calendars remained compatible even after the East-West Schism in 1054. Separations between the Roman Catholic ecclesiastical year and Eastern Orthodox liturgical calendar grew only over several centuries' time.