Axion estin (Greek: Άξιον εστίν, Slavonic: Достóйно éсть, Dostóino yesť), or It is Truly Meet, is a theotokion, i.e. a Hymn to Mary (sticheron composed in honor of the Theotokos, or Virgin Mary), which is chanted in the Divine Services of the Eastern Orthodox and Eastern Catholic Churches. It is also a style of icon of the Theotokos.
The hymn in Greek is:
Άξιον εστίν ως αληθώς
μακαρίζειν σε την Θεοτόκον,
την αειμακάριστον και παναμώμητον
και μητέρα του Θεού ημών.
Την τιμιωτέραν των Χερουβείμ
και ενδοξοτέραν ασυγκρίτως των Σεραφείμ
την αδιαφθόρως Θεόν Λόγον τεκούσαν,
την όντως Θεοτόκον,
One translation of the hymn goes as follows:
It is truly right to bless thee, O Theotokos,
ever blessed, and most pure, and the Mother of our God.
More honorable than the cherubim,
and beyond compare more glorious than the seraphim.
Without corruption thou gavest birth to God the Word.
True Theotokos, we magnify thee.
The second half of the hymn, beginning with the words, "More honorable than the cherubim..." is the older part of the hymn, and is an Irmos attributed to St. Cosmas the Hymnographer († 773). The introduction, "It is truly meet..." was, according to tradition, revealed by the Archangel Gabriel to a monk on Mount Athos.
The hymn is chanted at Matins, Compline, and other services; but its most important occurrence is at the Divine Liturgy, where it is chanted at the conclusion of the Anaphora. The second half of the hymn, "More honorable…" is frequently chanted before the dismissal which concludes services.
Icon and legend 
Axion Estin is also the name given to the icon of the Theotokos (Mother of God) before which, according to tradition, the hymn was revealed. It stands in the high place of the altar (sanctuary) of the katholikon (main church) of Karyes on Mount Athos.
According to tradition, an Elder and his disciple lived in a cell on Mount Athos. One Saturday night the Elder left to attend the All-Night Vigil in Karyes. He told his disciple to chant the service alone. That evening an unknown monk who called himself Gabriel, came to the cell, and they began the Vigil together. During the Ninth Ode of the Canon, when they began to sing the Magnificat, the disciple sang the original hymn "More honorable than the Cherubim…" and afterwards the visiting monk chanted it again, but with "It is truly meet…" preceding the original Irmos. As he sang, the icon began to radiate with Uncreated Light. When the disciple asked the visiting monk to write the words of the new hymn down, he took a roof tile and wrote on it with his finger, as though the tile were made of wax. The disciple knew then that this was no ordinary monk, but the Archangel Gabriel. At that moment the Archangel disappeared, but the icon of the Mother of God continued to radiate light for some time afterward.
The Eleousa ("merciful") Icon of the Mother of God, before which the hymn "It Is Truly Meet" was first chanted, was transferred to the katholikon (main church) at Karyes, known as the Protaton. The tile, with the hymn written on it, was taken to Constantinople when St. Nicholas II Chrysoberges was Patriarch (984-996). The hymn became integrated in the Eastern Orthodox worship books and since then it plays an important role in everyday worship, being chanted in the Divine Liturgy of St. John Chrysostom and recited at the Compline.
Feast Day 
Hymns in place of Axion Estin 
During the Divine Liturgy, Axion Estin is sometimes replaced by another hymn to the Theotokos. These hymns are referred to in the service books as "in place of Axion Estin" (Slavonic: Задостойнникъ, Zadostoinnik), or by the term "eis to Exairetos", meaning "at the Especially (petition)," from the petition that precedes them calling "especially" for the intercessions of the Theotokos.
At the Liturgy of St. Basil, it is replaced by the hymn:
All of Creation rejoices in thee, O full of grace:
the angels in heaven and the race of men,
O sanctified temple and noetic paradise,
the glory of virgins, of whom God was incarnate
and became a child, our God before the ages.
He made thy body into a throne,
and thy womb more spacious than the heavens.
All of creation rejoices in thee, O full of grace:
Glory be to thee.