For the defeat of Sihon see Numbers 21.21-26. Midian was the territory east of the Gulf of Aqaba, south of Edom. The rulers of Midian were subject to King Sihon (Revised Standard Version “the princes of Sihon”; compare New English Bible “the vassals of Sihon”).

It is not easy to put the contents of this verse into a very readable arrangement. If the proposed restructuring of verse 17-21a is adopted, then the form of Good News Translation may be followed from 21b onward: “It also included the whole kingdom….” Or a slightly different pattern may be used:

• It also included all of the territory ruled over from the city of Heshbon by King Sihon, the Amorite king. Five tribal leaders by the names of Evi, Rekem, Zur, Hur, and Reba had ruled part of this land for King Sihon. But Moses defeated King Sihon and all of these other leaders, and he took their territory.

Quoted with permission from Bratcher, Robert G. and Newman, Barclay M. A Handbook on Joshua. (UBS Helps for Translators). New York: UBS, 1983. For this and other handbooks for translators see here .