The influential figure in the abolition of slavery in the United Kingdom was William Wilberforce. A member of Parliament and a committed Christian, Wilberforce dedicated much of his political career to the abolitionist cause. He played a pivotal role in the movement that culminated in the passing of the Slavery Abolition Act in 1833, which made it illegal to buy or sell enslaved people in most of the British Empire. His efforts involved extensive lobbying, public speaking, and campaigning that raised awareness about the inhumanity of slavery, ultimately influencing public opinion and parliamentary action against the institution.