The sakkos, a short, close-fitting tunic with half sleeves, buttoned or tied with ribbons on the sides, and usually heavily embroidered, is adopted as an outer liturgical vestment by all Greek metropolitans in 1433.

Similar to the dalmatic worn by Roman Catholic deacons and possibly derived from the tunic of Eastern Roman emperors, it may also have been influenced by the Western deacon's dalmatic or the Jewish high priest's sleeveless tunic; small bells on the sleeves or sides imitate those worn by Jewish high priests.