2 Samuel 2:8-12

But Abner the son of Ner, commander of Saul’s army, had taken Ish-bosheth the son of Saul and brought him over to Mahanaim.

And he made him king over Gilead, over the Ashurites, over Jezreel, over Ephraim, and over Benjamin, even over all Israel.

Ish-bosheth, Saul’s son, was forty years old when he became king over Israel, and he was king for two years. The house of Judah, however, followed David.

And the time that David was king in Hebron over the house of Judah was seven years and six months. Civil War

Now Abner the son of Ner, went from Mahanaim to Gibeon with the servants of Ish-bosheth the son of Saul.