Horatio Southgate (July 5, 1812 – April 11, 1894) was born in Portland, Maine, and studied for the ordained ministry at Andover Theological Seminary as a Congregationalist.
[1] Southgate was consecrated as a missionary bishop "for the dominions and dependencies of the Sultan" (i.e., the Ottoman Empire) on October 26, 1844, following on several years of travels in what are now Turkey, Iran, Iraq and other parts of the Middle East.
His contacts with Jacobite, Nestorian, Assyrian and other Christian communities in this region marked significant early relations with the American Protestant Episcopal Church.
He was accompanied by other clergy of the Episcopal Church, including Samuel Penny, and engaged in controversy with other Anglo-American missionary groups in the region.
His son donated his papers to the Berkeley Divinity School, where they remain accessible through the Yale University Library.