Wilberforce was born in a house on the High Street of Hull, in the East Riding of Yorkshire, England, on 24 August 1759, the only son of Robert Wilberforce (1728–1768), a wealthy merchant, and his wife, Elizabeth Bird (1730–1798). His grandfather, William (1690–1774), had made the family fortune in the maritime trade with Baltic countries and in sugar refining. He was a partner in a business that built the Old Sugar House on Lime Street in Hull, which imported raw sugar from slave-based plantations in the West Indies. He was twice elected mayor of Hull.