Ahithophel was succeeded by Jehoiada son of Benaiah, then by Abiathar. Joab was the commander of the king's army.

2 Samuel 8:18
Benaiah son of Jehoiada was over the Cherethites and Pelethites; and David's sons were priestly leaders.

1 Kings 1:7
So Adonijah conferred with Joab son of Zeruiah and with Abiathar the priest, who supported him.

1 Chronicles 11:6
Now David had said, "Whoever is the first to strike down a Jebusite will become chief commander." And Joab son of Zeruiah went up first, and he became the chief.

1 Chronicles 27:5
The third army commander, as chief for the third month, was Benaiah son of Jehoiada the priest. There were 24,000 men in his division.

And after Ahithophel was Jehoiada the son of Benaiah, and Abiathar: and the general of the king's army was Joab.