Compilation for liturgical use of short Saints' lives, covering the Byzantine liturgical year. Probably commissioned by Byzantine emperor Constantine VII Porphyrogenitus (905-959).
The condensed lives of this Synaxarium are abridged even further in the early 11th century Menologion of Basil II.
Description in Wilhelm Studemund and Leopold Cohn: Verzeichniss der Griechischen Handschriften, vol. 1: Codices ex Bibliotheca Meermanniana Phillippici Graeci nunc Berolinenses (vol. 11 of Die Handschriften-Verzeichnisse der Königlichen Bibliothek zu Berlin), Berlin 1890, p. 96.
"Codex e duabus partibus compositus est:
[...] II. folia 13-300 [...] Synaxarium complectens vitas Sanctorum totius anni, a mense Septembri usque ad mensem Augustum.
[...] non idem est cum Menologio iussu Basilii imperatoris concinnato (Migne, tom. CXVII p. 20 sqq.)"
Fols. 1-12 of the Manuscript are from the 16th century;
fols. 13-300, that contain the synaxarium, are from the 12th-13th century.
(4.b) Delehaye 1902
Delehaye, Hippolyte (ed.): Synaxarium ecclesiae Constantinopolitanae. E Codice Sirmondiano nunc Berolinensi. Adiectis synaxariis selectis, Paris 1902, cols. 577-580.
The copy from Universitätsbibliothek Mainz is available on several platforms: