Then King Horam of Gezer came up to help Lachish, but Joshua struck down him and his army until no survivors remained.

the king of Eglon (one), the king of Gezer (one),

It then descended westward to Japhletite territory, as far as the territory of lower Beth Horon and Gezer, and ended at the sea.

The Ephraimites did not conquer the Canaanites living in Gezer. The Canaanites live among the Ephraimites to this very day and do hard labor as their servants.

They assigned them Shechem (a city of refuge for one who committed manslaughter) in the hill country of Ephraim, Gezer,