Saint Frumentius (in the Ge'ez language - ፍሬምናጦስ) and his brother Edesius were born sometime in the early 4th century. According to the historian Tyrannius Rufinus, around the year 316 AD the boys accompanied their uncle Meropius from modern day Lebanon (Then called Tyre) on a seafaring voyage to Ethiopia. At a stop over in one of the harbor towns of the Red Sea, the townspeople stormed the ship, massacred everyone but the two young boys and stole the ship. Saint Frumentius and his brother were sold into slavery and eventually ended up as slaves to the King of Axum.
It was here, at the capital Aksum the two boys became trusted slaves of the King. Edesius (sometimes known as Saint Aedesius) became a the royal cupbearer and Saint Frumentius the secretary of the King. Sometime near the end of his life, the King granted freedom to both brothers and after his death stayed on at the royal court at the beheast of the widowed king to help educate the heir, Ezana. During this time Saint Frumentius began using their positions to spread the Christian faith in the kingdom, first by encouraging travelling Christian merchants to openly practice their faith, then by finding worship places "according to the Roman rites". He is also credited with converting many people of the kingdom.
Once the prince was old enough to assume the throne, the two brothers departed the country and headed back towards Tyre. Saint Edesius was ordained a priest at Tyre and the two brothers travelled to Alexandria. At Alexandria, Saint Frumentius asked Saint Athanasius to send a bishop to the Ethiopian land to continue the conversions and preaching of the Gospel there. Saint Athanasius, after listening to the stories, decided that it was Saint Frumentius himself who would be best suited to the job and had him consecrated as a Bishop in the year 328 AD.
Saint Frumentius returned to Axum, making Aksum his episcopal see. He personally baptized King Ezana and aided the King in building churches and spreading Christianity. The very first monastery in Ethiopia was built by Saint Frumentius and was called Dabba Selama. Ethiopian traditions hold that Saint Frumentius completed the first translation of the Gospels into Ge'ez and became the first head of the Ethiopian Church with the title Abune. Today, his successors as head of the Ethiopian church likewise use this title. During his lifetime, Saint Frumentius was also called Kesate Birhan (Revealer of Light) and Abba Salama (Father of Priest) by the people of Ethiopian. He died in the year 383 AD.
His feast day is celebrated in the Catholic Church on October 27th.