Ikrimah ibn Abu Jahl was supposed to have been killed by the order of the Prophet but subsequently came to Mohammad (p), asked for forgiveness and he forgave him. One must note, Ikrimah was involved in a number of wars against the Muslims.
Mahmood Ahmad Ghadanfar:
Battle of Badr. Finally, things came to such a pass that the Battle of Uhud took place. Ikrimah bin Abu Jahl set off towards Uhud. He took his wife Umm Hakeem with him so that she could stand at the rear of the army ranks with the womenfolk of the other families who had suffered losses and beat the war – drums and excite the emotions of the young warriors of the Quraish.
They would fight with determination with the encouragement of the womenfolk and not flee the field of battle. The Quraish had placed khalid bin Waleed on the right of the armed forces and Ikrimah bin Abu Jahl on the left. In the battle of Uhud these two warriors created havoc among the ranks of the Muslims and gained the upper hand.
They gained great success that day and Abu Sufyan declared that they had avenged the defeat at Badr. 
THE ARMY OF THE QURAISH PREPARES
In the light of these successive failures, Quraish increased and accelerated their preparations for a decisive battle with the Muslims. At the turn of the year, everything was ready for the move. The Makkans also decided to take their women along with them for they might arouse them to fight manfully.
Thus a group of three thousand pitched warriors, of whom seven hundred were mailed soldiers and two hundred well-mounted cavalry with three thousand camels and fifteen women marched towards Madinah. The general leader was Abu Sufyan bin Harb, the cavalry was under the leadership of Khalid bin Al-Walid, assisted by Ikrimah bin Abu Jahl, and Bani Abdud-Dar were entrusted with the flag. 
Maulana Wahiduddin Khan:
Ikrimah ibn Abu Jahl who, following in his father’s footsteps, was an uncompromising opponents of Islam. Seeing that he was sure to meet his end in Makkah, he fled to the Yemen. His wife, Umm Bakim bint Barith, who had accepted Islam, appealed to the Prophet for asylum on behalf of her husband. Her request was granted, and she went to the Yemen to collect Ikrimah. He returned with her and became Muslim at the hand of the Prophet. 
 Commanders Of Muslim Army By Mahmood Ahmad Ghadanfar, page 191
 Sealed Nectar By Safi-ur-Rahman Al-Mubarakpuri, page 293
 Muhammad: A Prophet for All Humanity By Maulana Wahiduddin Khan, page 330 – 331