Hastings' Dictionary of the Bible (1898)
GAD, THE TRIBE OF. The territory, given to the tribe of Gad lay east of the Jordan, north of that allotted to Reuben, and south of that given to Manasseh on that side of the river. It extended from the Jordan eastward to Aroer, Josh 13:25, including half of Mount Gilead and half of Ammon. Deut 3:12; Josh 13:25. For physical features and history, see Gilead. Its chief cities were Ramoth-gilead, Mahanaim, Heshbon, and Aroer.
This tribe, in the Wilderness, was placed with Simeon and Reuben on the south of the tabernacle; with Reuben and the half of Manasseh, it occupied the pasture-grounds on the east of the Jordan. It was warlike, as is graphically stated, 1 Chr 12:8. Two famous men came from Gad — Barzillai, 2 Sam 17:27, and Elijah, 1 Kgs 17:1. The territory was the battle-field for wars between Syria and Israel. 2 Kgs 10:33.