TETRARCH (TETp&pX1)S)  , the ruler of a tetrarchy, that is, in the original sense of the word, of one quarter of a region . Such were the tetrarchies of Thessaly as reconstructed by Philip of Macedon and of Galatia before its conquest by the Romans (169 B.C.) . In later times the title of tetrarch is familiar from the New Testament as borne by certain princes of the petty dynasties which the Romans allowed to exercise a de-pendent sovereignty within the province of Syria . In this application it has lost its original precise sense, and means only the ruler of part of a divided kingdom, or of a district too unimportant to justify a higher title . After the death of Herod the Great (4 B.C.) his realm was shared among his three sons: the chief part, including Judaea, Samaria and Idumaea, fell to Archelaus (Matt. ii . 22), with the title of ethnarch (Josephus, Antiq., xvii . 11, 4); Philip received the north-east of the realm and was called tetrarch; and Galilee was given to Herod Antipas, who bore the same title (Luke iii . 1) . These three sovereignties were reunited under Herod Agrippa from A.D . 41 to 44 . In the same passage of Luke mention is made of Lysanias, tetrarch of Abilene near Damascus, in the valley of the Barada .