Neue Texte zum Computus byzantinischer Zeit im Codex Ambrosianus A 45 sup. Das originale Schreiben des Theophilos von Alexandria zum Ostertermin – Ein ägyptisches Paschalion 475–512 n. Chr. (adaptierte Ostertafel des Kyrill von Alexandria) – Die Trochoi zum Computus-Traktat des Presbyters Georgios

Abstract

“New Texts about the Byzantine Computus in Codex Ambrosianus A45 sup. The Original Letter from Theophilus ofAlexandria on the Easter Date – An Egyptian paschalion 475–512 CE (adapted Easter Table by Cyril of Alexandria) – Thetrochoi of Presbyter George’s Treatise on the Computus”: This paper investigates the computus texts of the Greek 12th-centurymanuscript A 45 sup of the Veneranda Biblioteca Ambrosiana. Due to its bad state of conservation the manuscript did not attractthe interest of researchers on Byzantine Easter calculations until now although it comprises a remarkable collection of the worksof various authors and preserves some texts as the sole witness. The most important findings are the original version of the letterby Theophilos of Alexandria to Emperor Theodosius I on the date of Easter, the solar and lunar wheels (trochoi) by the 6thcenturyauthor Georgios, presbyter of Constantinople (?), and a paschalion of Egyptian origin which reveals how the lost Eastertable by Cyril of Alexandria was composed.