Great feasts in the Eastern Orthodox Church
In the Eastern Orthodox Church, the feast of the death and Resurrection of Jesus, called Pascha (Easter), is the greatest of all holy days and as such it is called the "feast of feasts". Immediately below it in importance, there is a group of Twelve Great Feasts (Greek: Δωδεκάορτον).
Source: Wikipedia — Great feasts in the Eastern Orthodox Church (CC BY-SA 4.0)