Expedition of 'Abd al-Rahman ibn 'Awf
The expedition of ‘Abd al-Rahman ibn ‘Awf, also known as the Second Expedition of Dumatul Jandal took place in December, 627AD, 8th(Sha'ban) month of 6AH of the Islamic calendar. ‘Abd al-Rahman ibn ‘Awf was sent on a Mission to win over the Banu Kalb tribe and get them to adopt Islam and side with the Muslims, this operation was carried out successfully.
Source: Wikipedia — Expedition of 'Abd al-Rahman ibn 'Awf (CC BY-SA 4.0)