Basil was the eldest son of a remarkable Christian family of Cappadocia — his father a noted lawyer, his mother Emmelia later venerated as a saint, his elder sister St. Macrina the Younger a spiritual director of remarkable power, his younger brothers Gregory of Nyssa (a Father in his own right) and Peter of Sebaste. Four siblings became saints.
Educated at Constantinople and Athens, where he formed a lifelong friendship with Gregory of Nazianzus, he was on the path to a brilliant secular career when, in 356, he encountered Eustathius of Sebaste and was won to the ascetic life. He visited the monks of Syria, Egypt, Palestine, and Mesopotamia, then withdrew to a wild gorge on the river Iris in Pontus, where he wrote the Rule that would shape Eastern monasticism for all subsequent centuries.
Made bishop of Caesarea in 370, he built outside the city the 'New City' (Basileias) — a vast complex of hospitals, hospices, and homes for the poor that was the model for every medieval European hospital. He successfully defended Nicene orthodoxy against the pro-Arian emperor Valens, organised the response to a great famine, and wrote the Liturgy of St. Basil still used in Eastern churches several times each year. He died at fifty, exhausted by his labours, on the first day of the year 379.