After the Dutch attack Christopher Martin, a Devon merchant captain, built and maintained defensive batteries, King William’s Fort, at the entrance to the harbour at his own expense.

Martin landed six cannon from his vessel, Elias Andrews, and constructed an earthen breastwork and battery near chain Rock commanding the Narrows leading into the harbour.

During the Third Anglo-Dutch War, in 1673 Martin, with fewer than thirty men, successfully defended the harbour from a second Dutch attack and a separate raid by four pirate vessels.

The accession of William III and Mary II in 1688 brought about a reversal of British foreign policy, but although war was formally declared with France in 1689, little was achieved to give the English in Newfoundland better security from attack.

[2] The following year construction was begun on a well-engineered fortification - Fort William - which, when completed in 1700, had brick-faced ramparts, bomb-proof parapets, powder magazines and proper barracks.

The British garrison, demoralised and badly led, surrendered the fort after only a brief resistance, and the French, taking upwards of 500 prisoners with them,[3] withdrew to Placentia after destroying all the fortifications around the harbour.

During King George's War (1744–48) although no military action occurred in Newfoundland itself, the British had maintained a strengthened naval force in the colony as a counter to the fortress then established by the French at Louisbourg in Cape Breton, and Fort William was completely rebuilt by 1749.

British victories at Louisbourg (1758), Quebec City (1759) and Montreal (1760) virtually eliminated the French presence in North America and led to the opening of peace negotiations under conditions of great disadvantage to France.

Following earlier French-Canadian strategy, Comte d'Haussonville, the French commander, marched overland on St. John's from a landing in the undefended harbour at Bay Bulls.

Marching overland, Amherst drove the French from their outer defences at Quidi Vidi Pass and on the 15th captured the high ground of Signal Hill in a surprise dawn assault.