Today is the feast day of these two friends, who were both bishops and are now both doctors of the church.
The Breviary says:
Basil was born of a Christian family at Caesarea in Cappadocia in the year 330. Outstanding in learning and virtue he began to lead a retired life but in the year 370 he was appointed Bishop of Caesarea. He combatted the Arian heresy, wrote much of value, especially the monastic rules, which even today are followed by many monks of the Eastern Church; and he was outstanding in helping the poor. He died on 1 January 379.
Gregory was born near Nazianzus in the same year, 330. He journeyed much in order to acquire knowledge and he followed his friend Saint Basil in undertaking a life of solitude, but was ordained a priest and bishop. In 381 he was chosen Bishop of Constantinople. However, because of the divisions he encountered in the diocese he returned to his native Nazianzus where he died on 25 January in either 389 or 390. He was a man of outstanding knowledge and eloquence and was called The Theologian.