Jabalah IV ibn al-Ḥārith (Arabic: جبلة بن الحارث), known also by the tecnonymic Abū Shammar (أبو شمر), known in Byzantine sources as Gabalas (Greek: Γαβαλᾶς), was a ruler of the Ghassanids.
[4][8][9] With the outbreak of the Anastasian War against Sassanid Persia, the Ghassanids fought on the Byzantine side, although only one operation, an attack against the Lakhmid capital of al-Hirah in July 513, is explicitly attributed to them.
[10] The Ghassanids settled deep inside the Byzantine limes, and in a Syriac source for July 519 they are attested as having their "opulent" headquarters at al-Jabiya (Gabitha) in the Gaulanitis (Golan Heights), where Jabalah had succeeded his father as king over his tribe.
[11] With the rise of the pro-Chalcedonian Justin I (r. 518–527) to the imperial throne in 518 and the subsequent re-imposition of Chalcedonian orthodoxy throughout the Empire, however, the staunchly Monophysite Ghassanids withdrew from the alliance in c. 520 and retreated into the northern Hejaz.
Although the Ghassanids are not explicitly mentioned by the sources, the scholar Irfan Shahîd identifies Jabalah with the Arab phylarch known with the nickname al-Aṣfar (الأصفر), rendered in Greek as Tapharas (Ταφαρᾶς).