Axion Estin is a hymn with two layers and two histories. Its core is the stanza More Honourable Than the Cherubim and More Glorious Beyond Compare Than the Seraphim, which magnifies the Theotokos, who without corruption gave birth to God the Word, above the highest of the angels. That stanza is ascribed to Cosmas the Melodist, the eighth century hymnographer raised with John of Damascus, and it circulates throughout Byzantine worship, appearing daily in the office quite apart from the liturgy. The opening layer, It is truly meet to bless you, O Theotokos, ever blessed and most pure and the mother of our God, carries the famous story.
Athonite tradition tells that in the year 980, in a cell near Karyes on Mount Athos, a visiting stranger stood beside a monk at prayer and sang these unknown words before the icon of the Mother of God, wrote them, when no paper could hold them, with his finger on a roof tile as though on wax, and revealed himself as the Archangel Gabriel. The tile, the story says, went to Constantinople as proof, and the icon before which the words were first sung was enshrined in the Protaton church at Karyes, where, named Axion Estin after the hymn, it remains the chief icon of the Holy Mountain, honoured by all twenty monasteries as their common palladium.