Who was the father of Sufwan ibn Umaiya?

The father of Sufwan ibn Umaiya was Umaiya ibn Khalaf. Umaiya ibn Khalaf was a prominent figure in the Quraysh tribe of Mecca and is known for his opposition to the early Muslim community during the time of the Prophet Muhammad. Sufwan ibn Umaiya himself was also known for his initial hostility towards Islam but later became a Muslim after the conquest of Mecca.