The Holy Monastery was founded by Saint Philotheos, contemporary of Saint Athanasios the Athonite, and honors the memory of the Annunciation of the Most Holy Virgin (March 25th).
During the 16th century the Abbot, Saint Dionysios of Olympus, after many attempts, repopulated the monastery with many fathers.
The wonder-working icon of the Most Holy Mother of God «Glykofiloussa» (Sweet-kissing) is treasured in the Katholicon of the monastery. This icon had its origins in Constantinople and came to Philotheou via the waves of the sea.
In the library of the monastery there are preserved two scrolls containing the Liturgy of Saint Basil the Great.
The Saint equal-to-the-Apostles Kosmas Aitolos became a monk at Philotheou.