Unusually, Fahie's service was almost entirely spent in the West Indies, where he had been born and where he lived during the time he was in reserve and in his retirement.
Fahie was born in Saint Kitts, one of the Leeward Islands, the son of a judge and part of a prominent family of Irish settlers.
In 1777, aged 14, he was sent to serve in the Royal Navy during the American Revolutionary War, joining HMS Seaford under Captain John Colpoys.
Due to his knowledge of the island, Fahie was selected to take messages to the besieged garrison on Saint Kitts but was briefly captured in the attempt, before being released.
In 1793, at the outbreak of the French Revolutionary Wars, Fahie was given command of the sloop HMS Zebra, in which he participated in an attack on Fort-de-France, for which he was highly commended.
[1] In June 1810, Abercrombie escorted a convoy to Europe and was subsequently refitted in Britain, before join the squadron under Sir George Berkeley off Lisbon.
Briefly in reserve following the peace of 1814, Fahie returned to service during the Hundred Days as commander of the naval forces off Italy in HMS Malta.
Returning to the West Indies in reserve, Fahie was subsequently promoted to rear-admiral in April 1819 and made commander of the Leeward Islands Station the following year.