Dionysius the Areopagite
Numbered among the Seventy Lesser Apostles, Dionysius was baptized by St. Paul in Athens. Prior to this, Dionysius grew up in a notable family in Athens, attended philisophical school at home and abroad, was married with several children and was a member of the highest court in Greece, the Areopagus. After his conversion to the True Faith, St. Paul made him Bishop of Athens. Eventually he left his wife and children for Christ and went with St. Paul in missionary travel. He travelled to Jersusalem specifically to see the Most Holy Theotokos and writes of his encounter in one of his books. He was also present at her Dormition.
Seeing St. Paul martyred in Rome, St. Dionysius desired to be a martyr as well. He went to Gaul, along with his presbyster Rusticus and the deacon Eleutherius, to preach the gospel to the barbarians where his suffering was equalled only by his success in converting many pagans to Christianity. He built a small church in Paris where the Divine Services were celebrated.
In the year 96, St. Dionysius was seized and tortured for Christ, along with Rusticus and Eleutherius, and all three were beheaded under the reign of Domitian. St. Dionysius' head rolled a rather long way until it came to the feet of Catula, a Christian. She honorably buried it along with his body.
St. Dionysius wrote many famous books, including: The Divine Names of God, Celestial and Ecclesiastical Hierarchies and Mystical Theology. His feast day is October 3rd. His Letter to Titus is quoted by St. John of Damscus in his work On the Divine Images, a defense of icons during the iconocalstic controveries.