Abu Sufyan Ibn Harith was the paternal cousin of Prophet Muhammad (PBUH) and His companion. He is believed to have born around the same days of the birth of Prophet Muhammad (PBUH).
Abu Sufyan and Prophet Muhammad (PBUH) spent the childhood together. Even he was nursed by Haleema Sadia (R.A) for a brief time. However, after the announcing of Islam by Prophet (PBUH) he turned against Him and did everything possible to tease Prophet (PBUH) and Muslims. However, before the Muslims’ victory over Makkah, his heart changed and he went to accept Islam after asking for the forgiveness of Prophet (PBUH). He forgave him after a while, and afterwards Abu Sufyan became a true Muslim and fought bravely for Islam.
During the reign of Hazrat Umar (R.A), Abu Sufyan passed away and lies in peace at Jannatul Baqi.