A half-length portrait of Deane, to the right in armour, holding a baton in his right hand and resting his left hand on an anchor fluke. A column is implied on the left and a naval action is shown in the right background, which may indicate the Battle of Portland, 1653.

Deane was a Commonwealth soldier who commanded the Parliamentary artillery at the Battle of Naseby in 1642 and became Comptroller of Ordnance in the New Model Army. With Blake and Popham (also soldiers) he was appointed one of three Generals-at-Sea in 1649, which equated to the rank of admiral, and conveyed Cromwell's expedition to Ireland. He also commanded the fleet that supported Cromwell's Scottish campaign, played a leading role in the later Civil War and was active in bringing King Charles I to trial. On the outbreak of the First Anglo-Dutch War in 1652 he was given joint command of the fleet with Blake and they commanded at the Battle of Portland, 1653. Later that year he shared the command with Monck and was killed in action at his side in the 'Resolution', 85 guns, at the Battle of the Gabbard. He lay in state in the Queen's House, Greenwich.

Walker was a favourite painter of the Parliamentarian leaders during the Commonwealth and Protectorate, from 1649 to his death. His austere and candid portraits helped promote the image of simplicity bordering on severity that was demanded by Oliver Cromwell and his immediate circle. Although an image-maker for the Parliamentarian cause he nonetheless relied heavily on Van Dyck's portrait formulas and took compositions directly from his work.

This is true of the portrait of Deane which, except for the change of sitter, is a close copy of the prime 'landscape' version Van Dyck's portrait of Algernon Percy, Earl of Northumberland, as Lord High Admiral under Charles I (Alnwick Castle). Walker probably knew this directly, since it was not engraved, and in both works the positioning of the figure, the directness of the gaze and the vertical column in the background are characteristic Van Dyck devices. Van Dyck was also responsible, in his portraits of Percy, for introducing the anchor as a symbol of naval position and one which thereafter frequently recurs in naval portraits into the mid-19th century.