In 1673 and 1674 he represented his country at the Congress of Cologne, and in the latter year he became Secretary of State for the Northern Department, having practically purchased this position from Arlington for £6,000, a sum that he required from his successor when he left office in 1679. He served as Master of The Clothworkers' Company in 1676–77. In 1677, he became the second President of the Royal Society, but his main interests, after politics, were in antiquarian rather than in scientific matters.