Saint Theodosius was born in the province of Cappadocia in the village of Mogarissus. His parents Proheresius and Eulogia were very devout.
Endowed with a splendid voice, he zealously toiled at church reading and singing. St Theodosius prayed fervently that the Lord would guide him on the way to salvation. In his early years he visited the Holy Land and met with St Symeon the Stylite (September 1), who blessed him and predicted future pastoral service for him.
Yearning for the solitary life, Saint Theodosius settled in Palestine into a desolate cave, in which, according to Tradition, the three Magi had spent the night, having come to worship the Savior after His Nativity. He lived there for thirty years in great abstinence and unceasing prayer. People flocked to the ascetic, wishing to live under his guidance.
When the cave could no longer hold all the monks, St Theodosius prayed that the Lord Himself would indicate a place for the monks to live. Taking a censer with cold charcoal and incense, the monk started walking into the desert. At a certain spot the charcoal ignited by itself and the incense smoke began to rise. Here the monk established the first cenobitic monastery, or Lavra (meaning "broad" or "populous").
It was around this time that Theodosius' friend and countryman Sabbas the Sanctified was appointed Archimandrite of all the isolated monks in Palestine, by Patriarch Sallustius of Jerusalem (486-493). Therefore Theodosius was made the leader of all those monks who lived in community, and this was the origin of his being called "the Cenobiarch", which translates as chief of those living a life in common.