Liber Pontificalis

The Liber Pontificalis (Latin for Book of the Popes) is a book of biographies of popes from Saint Peter until the 15th century. The original publication of the Liber Pontificalis stopped with Pope Adrian II (867–872) or Pope Stephen V (885–891), but it was later supplemented in a different style until Pope Eugene IV (1431–1447) and then Pope Pius II (1458–1464). Although quoted virtually uncritically from the 8th to 18th century, the Liber Pontificalis has undergone intense modern scholarly scrutiny as an "unofficial instrument of pontifical propaganda." Some scholars have even characterized the Liber Pontificalis, like the works of Pseudo-Isidore and the Donation of Constantine, as a tool used by the medieval papacy to represent itself "as a primitive institution of the church, clothed with absolute and perpetual authority."

The title Liber Pontificalis goes back to the 12th century, although it only became current in the 15th century, and the canonical title of the work since the edition of Duchesne in the 19th century. In the earliest extant manuscripts it is referred to as Liber episcopalis in quo continentur acta beatorum pontificum Urbis Romae, and later the Gesta or Chronica pontificum.