“Adoni-zedek.” “Adoni-zedek” is a typically Semitic name, and it means “My lord is righteousness.” Interestingly, Adoni-zedek ruled Jerusalem just as Melchi-zedek (“My king is righteousness”), who is better known as “Melchizedek” ruled Jerusalem some 450 years earlier. Adoni-zedek is called, along with the other kings, an Amorite (Josh. 10:5). They probably had tribal connections as well as geographical ones. The Hivites (some of whom lived in Gibeon) were “cousins” to the Amorites. Ham gave birth to Canaan (Gen. 10:6), and Canaan then fathered his firstborn, Sidon, then Heth (the Hittites come from Heth), the Jebusites (who lived in and around Jerusalem), the Amorites (who generally lived in central Israel, in the hill country; cp. Num. 13:29, Deut. 1:7, 19, 20, 44; Josh. 5:1, 7:7), the Girgashites, the Hivites, the Arkites, the Sinites, the Arvadites, the Zemarites, and the Hamathites (Gen. 10:15-18). Over time, “the clans of the Canaanites were spread abroad” and populated a lot of the Promised Land (Gen. 10:18).
The presence of Adoni-zedek in Jerusalem is likely more than a coincidence, and demonstrates the war going on between good and evil. During the time of Abraham, it became clear that God wanted the land of Israel for His people, so the Devil went after it too. At the time of Abraham the Canaanites were already living in Israel (Gen. 13:7), but Melchizedek was a godly king. But by the time of Joshua the native Canaanite population had become so wicked and infiltrated by the Nephilim that God commanded to kill everyone that breathed (Deut. 20:16-17; Josh. 10:40; 11:11, 14).
[For more on the Nephilim and why God commanded that all the people in the Promised Land be killed, see commentary on Gen. 6:4, “Nephilim.”]
“king of Jerusalem.” This is the first time in the Bible that “Jerusalem” was called by that name. Although the name “Jerusalem” is said to mean “City of Peace,” (the ancient meaning of the name Jerusalem has been lost in history and today its meaning is debated by scholars), through the millennia, Jerusalem has been anything but a city of peace. There have been long successions of ungodly rulers and war after war in which Jerusalem is involved.