ChristianAnswers.Net WebBible Encyclopedia
strictly, the ruler over the fourth part of a province, but the word denotes a ruler of a province generally (Matt. 14:1; Luke 3:1, 19; 9:7; Acts 13:1)
Herod and Phasael, the sons of Antipater, were the first tetrarchs in the Land of Israel. Herod the tetrarch had the title of king (Matt. 14:9).