Αθανάσιος Αλεξανδρείας, also known as Saint Athanasius, was a prominent Christian theologian and bishop of Alexandria in the 4th century. He is best known for his strong opposition to Arianism, a belief that denied the divinity of Jesus Christ. Athanasius played a crucial role in the development of early Christian doctrine and was a key figure at the First Council of Nicaea in 325 AD. Athanasius was exiled multiple times due to his beliefs and conflicts with various emperors. He is celebrated as a Doctor of the Church and is recognized for his writings, including the famous work "On the Incarnation." His legacy continues to influence Christian theology and the understanding of the nature of Christ.