Easton's Bible Dictionary (1897)
Lord of justice or righteousness, was king in Jerusalem at the time when the Israelites invaded Palestine (Josh. 10:1, 3). He formed a confederacy with the other Canaanitish kings against the Israelites, but was utterly routed by Joshua when he was engaged in besieging the Gibeonites. The history of this victory and of the treatment of the five confederated kings is recorded in Josh. 10:1-27. (Comp. Deut. 21:23). Among the Tell Amarna tablets (see EGYPT) are some very interesting letters from Adoni-zedec to the King of Egypt.
These illustrate in a very remarkable manner the history recorded in Josh. 10, and indeed throw light on the wars of conquest generally, so that they may be read as a kind of commentary on the book of Joshua. ” Then he implores the king of Egypt to send soldiers to help him, directing that the army should come by sea to Ascalon or Gaza, and thence march to Wru-sa-lim (Jerusalem) by the valley of Elah.