Theodosius the Cenobiarch was a monk, abbot, and saint who was founder and organizer of the Cenobitic way of monastic life.

He was born in Mogarissos, a village in Cappadocia, Saint Basil's province. Theodosius' parents Proheresius and Eulogia were both very pious. Later Eulogia would become a nun taking her son Theodosius as her spiritual father.

When he was young, he wanted to imitate Abraham by leaving his parents, friends, relatives and everything else for the love of God.

Theodosius set out for Jerusalem at the time of the Holy Fourth Ecumenical Council of Chalcedon held in 451.

After reaching Antioch, he went to see Saint Symeon the Stylite, to ask for his prayers and blessing. While he arrived at the pillar of Saint Symeon, he was miraculously greeted by name and was invited to ascend the column. Theodosius climbed the pillar and prostrated himself before Saint Symeon who embraced him with his blessing and prophesied great spiritual glory for Theodosius.

Later, he travelled to Jerusalem and started visiting the Holy places. Theodosius began his monastic labours under the hermit abbot Longinus, settling near the Tower of David. Having decided to live a life of solitude, he settled on the peak of a mountain and lived in a cave. There is a tradition from the ancient fathers that this was the same cave the three Magi spent the night after they had worshiped the Lord, and that an angel was sent there and ordered them to return to their own country by another way, which they did.

While dwelling in the cave, Theodosius performed great feats of asceticism. He prayed at all times and ate only enough so that he would not fall ill from extreme fasting.

Theodosius formed a small community of monks near Bethlehem, which later became the Monastery of St. Theodosius. The community grew rapidly and became very well known for its work with the sick, elderly, and mentally impaired. Theodosius was made the leader of the community. This was the origin of his being called "the Cenobiarch", which translates as chief of those living a life in common.

Theodosius was a staunch opponent of Monophysitism, which caused the emperor Anastasius to remove him from office temporarily.

When he was at the age of ninety, the emperor exiled Theodosius and he took refuge in Lebanon.

Theodosius died near Jerusalem, at about 105 years old.

Other saints of the day
1. Saint Alexander
2. Saint Anastasius X
3. Saint Honorata
4. Saint Leucius of Brindisi
5. Saint Eithne