Saint Theodosius of Antioch in his early years left the rich home of his illustrious parents and entered upon the straight and arduous path of asceticism. He settled into a small cell on the shore of the Gulf of Isska, near the city of Ossos. The saint weakened his body with prostrations and by lying upon the bare ground. He also wore a hairshirt and heavy iron chains. His hair grew so long that it covered his feet.
By continuous feats of fasting and prayer he conquered his fleshly and spiritual passions, he quieted his temper, and drove away unclean thoughts. He labored much, tilling his garden and occupying himself with plaiting ropes. In his native land Saint Theodosius founded a monastery (Skupela). He imparted to the monks a love for physical toil and for spiritual deeds. Saint Theodosius had a special concern for strangers.
The sublime life of the saint was known even beyond the confines of the monastery. Both Christians and pagans knew him. Seafarers in time of peril called out for help to “the God of Theodosius.” It happened that at the mere mention of Saint Theodosius, the waves of the sea were calmed. Brigands feared and respected him, and sought his prayers. Fleeing the praise of people, the saint settled near the village of Maraton, founding here the Maratonia monastery. There the great ascetic peacefully finished the days of his God-pleasing life (412).