The victory of the Hanoverians over the Jacobites marked the beginning of the Whig Ascendancy which lasted for much of the 18th century. Because the Tory opposition had been tainted, in the eyes of George I, by their support of the Jacobite pretenders, he did not trust them and drew all of his ministers and officials from the Whigs. Following their victory, the Whigs split with one group forming the government for George I, and the other dissident Whigs became the effective opposition in Parliament. After a period of political manoeuvring, he was for a while associated with a Whig faction led by James Stanhope, but from 1720, Newcastle began to identify strongly with the government Whigs, who had quickly come to be dominated by Sir Robert Walpole.