[1][2][3][4] The fort, originally intended to be named Fort William was built on a hilltop between Government Hill (from which Government House had moved to Mount Langton in Pembroke Parish with the move of the Parliament of Bermuda and the colonial capital from St. George's Town to the then Town of Hamilton in 1815) and Barrack Hill, the site of the Royal Barracks of St. George's Garrison.

The Royal Navy spent a dozen years surveying the reef, identifying a channel (originally called Hurd's Channel after then-Lieutenant Thomas Hannaford Hurd, the officer who had located it, but now referred to as The Narrows) suitable for ships-of-the-line to enter the Northern Lagoon, the Great Sound, and Hamilton Harbour before establishing a base at Bermuda in 1795.

Although the Admiralty began buying and leasing land at Bermuda's West End, on the Great Sound, for the eventual construction of the Royal Naval Dockyard, the lack of development and infrastructure there meant the Navy used St. George's as its base pending the construction of the dockyard on Ireland Island.

Fort William, on the northern side of the town and Fort George at Mount Hill (or Riche's Mount) on the western side, both overlooking the harbour, and to a greater or lesser degree the northern lagoon to the north of the island (the area of enclosed water immediately to the north of St. George's Island is called Murray's Anchorage, and had been the anchorage for the naval squadron of the North America Station when the naval base was at St. George's).

An earlier magazine had existed on Government Hill, from which a hundred barrels of gunpowder was stolen during the American War of Independence and supplied to the rebels in a plot organised by Henry Tucker and Benjamin Franklin.

The Western Redoubt would house a restaurant called The Gunpowder Tavern, but has been vacant and increasingly derelict since the 1990s, although it is now part of the UNESCO World Heritage Site the Historic Town of St George and Related Fortifications).