British Prime Minister William Pitt's focus on the colonies for the 1758 campaign pays off with the taking of Louisbourg after French reinforcements are blocked by British naval victory in the Battle of Cartagena and in the successful capture of Fort Duquesne and Fort Frontenac.

The British also continue the process of deporting the Acadian population with a wave of major operations against Île Saint-Jean (present-day Prince Edward Island), the St. John River valley, and the Petitcodiac River valley.

The celebration of these successes is dampened by their embarrassing defeat in the Battle of Carillon (Ticonderoga), in which four thousand French troops repulse sixteen thousand British.

When the British, led by generals James Abercrombie and George Howe, attack, they believe that the French led by general Marquis de Montcalm are defended only by a small abatis that can be taken easily given the British force's significant numerical advantage.

The British offensive, which is supposed to advance in tight columns and overwhelm the French defenders, falls into confusion and scatters, leaving large spaces in their ranks.

When the French Chevalier de Levis sends a thousand soldiers to reinforce Montcalm's struggling troops, the British ae pinned down in the brush by intense French musket fire and they are forced to retreat.

The French plan to defend Louisbourg by a large naval build-up, as they had in 1757.

However, the French fleet sailing from Toulon is blockaded in Cartagena by a British force, and a relief force had been defeated at the Battle of Cartagena.

After this the French abandon their attempt to reinforce Louisbourg from the Mediterranean, meaning there will be few ships available to actively oppose the British off Louisbourg.