Judges 9:34
And Abimelech rose up, and all the people that were with him, by night, and they laid wait against Shechem in four companies. And Abimelech rose up, and all the people that were with him, by night, and they laid wait against Shechem in four companies.
Shechem was a very ancient place where Jacob had stopped on his return from Padan-aram to Canaan. Abimelech was the son of Gideon's maid, and he had Gideon's sons, his own brothers, slain so that he might become ruler of Israel, yet the men of Shechem chose him as ruler. The attack described in the verse came after Shechem rebelled against Abimelech.
The verse describes Abimelech rising up with all the people that were with him by night to lie in wait against Shechem in four companies. That ambush utterly destroyed Shechem, slaughtering its inhabitants and reducing the city to ashes. The ground was then sown with salt as a sign of lasting desolation.