Tetrarch Strictly the ruler over the fourth part of a province; but the word denotes a ruler of a province generally (Mat 14:1; Luk 3:1, Luk 3:19; Luk 9:7; Act 13:1). Herod and Phasael, the sons of Antipater, were the first tetrarchs in Palestine. Herod the tetrarch had the title of king (Mat 14:9).