Unlike the majority of the tribes, the land of Reuben, along with that of Gad and half of Manasseh, was on the eastern side of the Jordan and shared a border with Moab.

The Book of Joshua records that the tribes of Reuben, Gad and half of Manasseh were allocated land by Moses on the eastern side of the Jordan River and the Dead Sea.

[5] The territories described in Joshua 13 depict Gad as being to the north of Reuben, while the description in Numbers 32 and 34 has Reubenites living near Heshbon, surrounded by Gadites.

[22] Israel Finkelstein et al., have claimed that lack of evidence for a systematic conquest or the abrupt appearance of a new culture indicates that the Israelites simply arose as a subculture within Canaanite society.

In this period, according to the ancient Song of Deborah, Reuben declined to take part in the war against Sisera, the people instead idly resting among their flocks as if it were a time of peace, though the decision to do so was taken with a heavy heart.

Having subjected the occupants to a siege, the population sought terms for surrender, and were told by Nahash that they had a choice of death (by the sword) or having their right eyes gouged out.

The occupants sought help from the people of Israel, sending messengers throughout the whole territory, and Saul, a herdsman at this time, responded by raising an army which decisively defeated Nahash and his cohorts at Bezek.

A more complete explanation came to light with the discovery of the Dead Sea Scrolls: although not present in either the Septuagint or masoretic text, an introductory passage, preceding this narrative, was found in a copy of the Books of Samuel among the scrolls found in cave 4:[25] [N]ahash, king of Ammonites would put hard pressure on the descendants of Gad and the descendants of Ruben and would gouge everyone's right eye out, but no res(cuer) would be provided for Israel and there was not left anyone among the children of Israel in the Tr(ans Jordan) whose right eye Nahash the king of Ammonites did not gouge out but be(hold) seven thousand men (escaped the power of) Ammonites and they arrived at (Ya)besh Gilead.

[28] According to 1 Chronicles 5:26, Tiglath-Pileser III of Assyria (ruled 745–727 BC) deported the Reubenites, Gadites, and the half-tribe of Manasseh to "Halah, Habor, Hara, and the Gozan River."