The article presents data about the inheritors of the Old Bulgarian Prayers for Every Occasion which are known to scholars thanks to the Glagolitic Euchologium Sinaiticum from the 10th century. They were discovered in the manuscript prayer- and divine service books kept in the Zograf library on Mount Athos. The respective euchological texts are described in the manuscripts in chronological order by century; they are identified in accordance with their Glagolitic prototypes and their Greek parallels are given.