Complex sentence: The oath of allegiance which the recipient of the pallium takes today apparently originated in the eleventh century, during the reign of Paschal II (1099--118), and replaced the profession of faith.
Split into simpler sentences: The oath of allegiance which the recipient of the pallium takes today apparently originated in the eleventh century. It is met with during the reign of Paschal II (1099--118), and replaced the profession of faith.