Sir Henry came from a family with a seafaring tradition and went to sea in 1800 at age 14 aboard the 32-gun frigate, HMS Maidstone. And being the son of Admiral Duncan gave him the internal patronage he needed to rise quickly in rank. He was already a lieutenant by his father’s death in 1804 and was quickly appointed commander in November 1804. He was promoted to post rank while serving under Admiral Sir Cuthbert Collingwood in 1806.
By the time our story takes place in 1813, he was a 27 year old captain of seven year’s seniority commanding the HMS Imperieuse, a 38-gun frigate previously commanded by Lord Cochrane and which was formerly the Spanish Medea taken as a prize when Captain Graham Moore’s squadron seized the Spanish treasure fleet on October 5, 1804.
For some days from the end of September 1813 Captain Duncan in Imperieuse (38), along with his squadron consisting of Resistance (38), Swallow (18), Eclair (18) and Pylades (16) under his command, had been watching a convoy in the port of Anzio and waiting for an opportunity to attack. He was joined on 5 October by Captain George H. L. Dundas in HMS Edinburgh (74), who, although the senior officer, agreed to support Duncan’s plan.
A few nights earlier Lieutenant Travers of Imperieuse, with the small cutter and seven men, had attacked a tower with one gun, probably Tor Caldara located on the high ground at the left of the above picture, by sticking a Congreve rocket with the stick cut short through a window. The smoke forced the defenders to let down the drawbridge and they were captured one by one as they came out. The tower was destroyed and sixteen of the garrison – all he could cram into the small boat – were taken prisoner. They provided essential information about the defenses – two batteries, each mounting three heavy guns, on a mole; a tower to the north with one gun and a battery to the south with two.
At half past one in the afternoon of the 5 October Imperieuse and Resistance took station off the mole, Swallow off the tower and Eclair and Pylades to the south battery, with Edinburgh supporting the last two ships. The ships opened fire together on a signal and a landing party of seamen and marines under Lieutenant Travers of Imperieuse and Captain Mitchell of Edinburgh’s Marine detachment, took the southern battery which was immediately deserted by the enemy. While this was happening another landing party stormed the two batteries on the mole. The fortifications were all destroyed and the landing parties returned to their ships without loss of life.
In all, 29 vessels were capture of which 20 were carrying timber for the French dockyard in Toulon.