A three-quarter-length portrait to left in a rust-red velvet coat with silver embroidered button-holes and buttons. He has a brown full-bottomed wig and is leaning on a gun barrel, holding his baton in both hands. In the left background is a three-decker in action is implied, with a blue flag at the mizzen.

He commanded the 'Kent', 70 guns, on Rooke's expedition to Cadiz in 1702, and which was one of the ships that destroyed the Franco-Spanish fleet in Vigo Bay. In 1704 while serving on the 'St George', 96 guns, he played a conspicuous part in the action with the French off Malaga, for which he was knighted. Jennings was regarded as one of the greatest seamen of his age, despite having few opportunities to distinguish himself as a fighting fleet commander. As a vice-admiral and later Admiral of the White he was in command at Lisbon, 1708-10, was commander-in-chief in the Mediterranean in 1713 and a Lord of the Admiralty, 1714-27. In 1720 he was appointed Ranger of Greenwich Park and Governor of Greenwich Hospital, the last man to combine the posts and live in the Queen's House although he was occasionally at sea until 1727. In 1714 the Hospital bought an 11-ton block of marble taken from the French by Rooke, reportedly for a statue of William III which was never made, and in 1735 Jennings personally paid Rysbrack £400 to carve it into a statue of George II. This was installed that year in the Grand Square, where it remains although now badly eroded. Jennings was the Hospital's longest-serving Governor and died in office in 1743.

This portrait is one of nine by Kneller and seven by Michael Dahl commissioned by Queen Anne and her husband and Lord High Admiral, Prince George of Denmark, of the leading admirals of her reign (1702-14). When presented to Greenwich Hospital in 1824 by George IV, the set also included a three-quarter-length portrait of George himself in Garter robes by Dahl. All were transferred to the Museum's care as part of the Greenwich Hospital Collection except the portrait of George, which remains on loan to the Old Royal Naval College from the Hospital.