 Despite Grantham's marriage to the sister of one of the most notorious participants in the 1715 Jacobite rising, George I appointed him Lord Chamberlain to the household of Caroline, Princess of Wales in 1717, and Grantham retained his position when the Prince of Wales succeeded as King George II in 1727 and the Princess became Queen Caroline.He remained her Lord Chamberlain until her death in 1737.Grantham later involved himself in a project to create an orphanage for abandoned children in London, the first of its kind in the nation.