Marcellinus of Carthage was a Roman military tribune and secretary of state who served under Emperor Honorius. Born in Toledo, Spain, he was a cultured aristocrat with a deep interest in theology. He maintained close friendships with prominent religious figures, including Saint Jerome and Augustine of Hippo, to whom he was a frequent correspondent. While presiding over the Council of Carthage in 411, he ruled against the Donatists, enforcing imperial policy that declared them heretics. His involvement in these religious and political disputes eventually led to his death in 413.