Ramsay was brought to the attention of the royal family by one of his most important patrons, John Stuart, 3rd Earl of Bute, who in 1758 commissioned a portrait of George III when Prince of Wales, a version of which is in the Royal Collection (409153). Through an error John Shackleton (who died in 1767) was reappointed to the post of Principal Painter in Ordinary to George III on his accession in 1760. Ramsay, however, was given the title ‘one of His Majesty’s Principal Painters in Ordinary’ and assumed the duties of the King’s painter. The strength of Ramsay’s position in the King’s household is illustrated by George III’s refusal of Lord Eglinton’s request that he sit to Ramsay’s younger rival, Reynolds, with the words: ‘Mr Ramsay is my painter, my Lord.’ Lord Bute also introduced Johan Zoffany (1733-1810) to the King, but whereas Zoffany was at the outset of his career, Allan Ramsay was already fifty when he found himself superintending the productions of innumerable copies of his state portraits of the King and Queen (OM 996-7, 405307-8). This means that beyond these there are disappointingly few original portrait compositions by him in the collection – a group of Queen Charlotte and her two eldest children (OM 998, 404922) and three individual portraits of standard three-quarter-length format (50 x 40 inches) of members of her family (OM 999-1001, 404924, 406963 and 403553). These three were painted in 1767-9 and are probably the 'other portraits' for which Ramsay was paid £152 15s in February 1769.

This portrait of c. 1767 shows the two-year-old Prince William (future William IV) as a boisterous baby beating a drum (decorated with the royal cipher) in what is otherwise a quiet and elegant setting (the contrast perhaps deliberate). The painting of the English silver-gilt hot water urn (what the Russians would call a 'Samovar') and china tea-cups and cream jug is especially subtle - the detail never asserting itself against the harmonious and soft half-light of the scene as a whole. The drum rests on a little stool over which is draped an ermine-lined mantle. Like the portrait of Queen Charlotte with her two eldest sons (OM 998, 404922), the head was executed on a separate piece of canvas and stitched into the larger composition.