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