He controlled offices and pensions.

With these things he bought members and he had to keep them bought by repeating the benefits.

If the holder of a public office was thought to be dying the King was already naming to his Prime Minister the person to whom the office must go when death should occur.
He insisted that many posts previously granted for life should now be given during his pleasure so that he might dismiss the holders at will.
He watched the words and the votes in Parliament of public men and woe to those in his power if they displeased him.

When he knew that Fox, his great antagonist, would be absent from Parliament he pressed through measures which Fox would have opposed.

It was not until George III was King that the buying and selling of boroughs became common.