Paul the Deacon, also known as Paulus Diaconus, Warnefridus, Barnefridus, or Winfridus, and sometimes suffixed Cassinensis, was a Benedictine monk, scribe, and historian of the Lombards.

Monte Cassino is a rocky hill about 130 kilometres (80 mi) southeast of Rome, in the Latin Valley, Italy, 2 kilometres west of Cassino and at an elevation of 520 m (1,710 ft). Site of the Roman town of Casinum, it is widely known for its abbey, the first house of the Benedictine Order, having been established by Benedict of Nursia himself around 529. It was for the community of Monte Cassino that the Rule of Saint Benedict was composed.