A lifelong courtier, Irby served for nearly 50 years in the households of George I, Frederick, Prince of Wales, and the Princess Dowager, of whom Horace Walpole calls him ‘the Polonius.’1Walpole, Mems. Geo. II, i. 87. Returned on petition for Launceston in 1735, he followed his master, the Prince of Wales, into opposition in 1738, voting against the Government except on the motion for Walpole’s dismissal in February 1741, when he withdrew. After Walpole’s fall he supported the Government, reverting to opposition with Frederick in 1747. In that year he was included among the followers of the Prince who were to be brought by him into Parliament, not being able to bring in themselves. After rejecting an invitation to stand for Queenborough,2HMC Fortescue, i. 108, 109. he was brought in by Thomas Pitt for both Old Sarum and Bodmin, opting to sit for Bodmin, where he eventually established a strong personal interest. In the 2nd Lord Egmont’s lists of promotions on Frederick’s accession he is put down for a peerage, which he secured on George III’s accession.
He died 30 Mar. 1775.