Collectio Avellana is a collection of 244 documents, dating from AD 367 to 553, that includes many imperial letters written to pope

Pope

The Pope is the Bishop of Rome, a position that makes him the leader of the worldwide Catholic Church . In the Catholic Church, the Pope is regarded as the successor of Saint Peter, the Apostle...

s and others, imperial acts and papal letters and other documents that were gathered just after the mid- 6th century. Many of the documents have not been preserved in any other collection. Contemporary copies have not survived: the oldest and best manuscript is in the Vatican Library

Vatican Library

The Vatican Library is the library of the Holy See, currently located in Vatican City. It is one of the oldest libraries in the world and contains one of the most significant collections of historical texts. Formally established in 1475, though in fact much older, it has 75,000 codices from...

, Vat. lat. 3787 (XI). This is the text that was edited by O. Guenther, Epistolae Imperatorum Pontificum Aliorum Inde ab a. CCCLXVII usque DLIII datae Avellana Quae Dicitur Collectio, in Corpus Scriptorum Ecclesasticorum Latinorum, Vol. 35, in 2 parts (Prague/Vienna/Leipzig, 1895). The compiler(s) of Collectio Avellana aimed to fill the gaps of previous compilations. The author or authors must have had access to archives of the See of Rome, since they incorporated into the collection a variety of papal documents not in Liber Pontificalis

Liber Pontificalis

The Liber Pontificalis 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 or Pope Stephen V , but it was later supplemented in a different style until Pope Eugene IV and then Pope Pius II...

and imperial acts.