The church of Protaton is the oldest Catholicon in Mt. Athos and is dedicated to the Dormition of the Virgin. It was probably erected during the first half of the 10th century, renovated in the era of Andronicus Palaeologos, while restoration works were also undertaken in 1955, where a square was created in the place of the cells adjacent to Protaton, to promote the latter. It differs from the Catholicon of the monasteries on Mt. Athos in being a triple-aisled basilica with an elevated middle aisle, that permits the third row of openings on its perimeter. Its present day form combines the type of the basilica, with respect to its roof, with a cross shaped ground plan. Its interior stands out for four pessaries divide the cross-shaped church into a central space with corner rooms. The church is adorned with awe inspiring frescoes, dating from the 14th century, and painted by Manuel Panselinos, the key representative artist of the Macedonian School, while its icon screen, or templon, is marble and a well preserved expression of old Byzantine icon screens. Kept on the synthronon in the Holy Bema is the miracle working icon “Axion Esti”, which dates, according to tradition, back to the 10th century and is the symbol of the Holy Mountain. The church has two narthexes which date from the early 16th century, one on its western side in the form of a adit and another on its northern side, where there is a cenotaph for the monks who were slaughtered by Catalan pirates in the 14th century. The bell tower was erected in 1534 by Seraphim and later renovated. In the tower of Protaton there is a library with 117 manuscripts, of which 47 are parchments. Kept in its archive room is the 1st Typikon (liturgical book) for Mt. Athos by Emperor John Tzimiskes, also known as “billy goat” for it is written on billy goat skin and constitutes the most historic text in this land.