Encyclopædia Britannica, Ninth Edition/Tetrarch

TETRARCH (τετράρχης), the ruler of a tetrarchy (τετραρχία), that is, in the original sense of the word, of one quarter of a region. 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 dependent 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 region too narrow to support 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 Judæa, Samaria, and Idumea, fell to Archelaus (Matt. ii. 22), with the title of ethnarch; 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 41 to 44 A.D. Another tetrarchy is mentioned in Luke iii. 1, viz., that of Lysanias in the little district of Abilene, near Damascus, in the valley of the Barada. An inscription of this Lysanias is given in C. I. Gr., 4521.

See Renan, Mém de l'Acad., xxvi. 2 (1870), p. 49 sq.