St. Hilary of Poitiers was a 4th century Christian bishop and theologian. He was born in Poitiers, France and is considered one of the most important figures of the Western Church in the 4th century. He was a key figure in the development of Western Christianity and his writings and teachings had a significant impact on the development of Christian theology.
St. Hilary is best known for his defense of the doctrine of the Trinity against the Arian heresy, which denied the full divinity of Jesus Christ. He is also known for his commentaries on the Psalms and his On the Trinity, a treatise that is considered one of the most important works of early Christian theology. He was also a great preacher, and his sermons were famous for their eloquence and clarity.
He was exiled by the Emperor Constantius II for his opposition to Arianism, and spent several years in Phrygia (modern-day Turkey) where he continued his work on the defense of the trinitarian doctrine. He returned to Poitiers after the death of the Emperor, and continued to write and preach until his death. He is venerated as a saint in the Roman Catholic Church, Anglican Communion, and Eastern Orthodox Church.
