Despite overseeing the Royal Navy's victory at the Glorious First of June in 1794, he faced criticism for his handling of the Admiralty and was demoted to the comparatively unimportant post of Lord Privy Seal.

This became a key role in the next few years when a French invasion appeared imminent, and he helped oversee Britain's defences including the construction of a series of martello towers.

In 1809 he did accept command of an expedition to the island of Walcheren, as part of a plan to strike at a French fleet being assembled in nearby Antwerp.

Despite overseeing the largest force Britain had despatched abroad during the war, the expedition became bogged down on the island and began suffering heavy casualty rates due to disease.

Although Europe was at peace by this time, Gibraltar remained a key strategic post, and he oversaw improvements to the defences while also dealing with a difficult diplomatic relationship with neighbouring Spain which was going through a period of political turbulence.

In 1766 his father returned to office as Prime Minister, taking the title of Earl of Chatham which John also became heir to styled as Viscount Pitt.

[1] He served as aide-de-camp to General Guy Carleton in Quebec, where they made preparations to resist a planned invasion by American forces.

In October 1775 he departed for London carrying dispatches, missing the Battle of Quebec that took place at the end of the year where Carleton successfully defended the city.

[8] Back in Britain, under strong family pressure, Pitt resigned his commission in early 1776 in protest against the war with America, to which his father was vehemently opposed.

On 7 April he and his younger brothers were in attendance when their father rose in the House of Lords to give a speech, in which he called for defiance against the French.

In John Singleton Copley's painting The Death of the Earl of Chatham, Pitt is portrayed in military uniform at his father's side.

[12] Having succeeded to the Earldom, Chatham spent the following year in Gibraltar before transferring to the West Indies with a newly raised regiment, the 86th Foot.

Although he was appointed colonel in October 1793 and major general in February 1795, Chatham does not appear to have undertaken any military duties for nearly fifteen years after the end of the War of American Independence in 1783.

In February 1784 on the way back from an event in the City of London, the brothers were attacked by a mob likely organised by supporters of their rival Charles James Fox.

Due to his wife's severe illness, Chatham did not consider himself able to join his brother's government for the next few years, despite rumours linking him to various posts.

In gratitude for the successful resolution of the crisis in Britain's favour, George III wanted to award the Order of the Garter to the Prime Minister.

Due to miscommunication between the Board of Ordnance and the Admiralty, the ships carrying siege weaponry and supplies for the besieging forces arrived two weeks late.

Their meeting was not productive and Chatham considered refusing his new office, shattering the image of unity in the cabinet that Pitt wanted to project.

Nonetheless, there was a lack of the old warmth between them, and Chatham increasingly took an independent line in the cabinet where he had previously been a close supporter of Pitt.

[36] Here he stayed, remaining in office after Pitt's resignation under Henry Addington, until a cabinet reshuffle in June 1801 moved him to the post of Master-General of the Ordnance.

Commanded by the Duke of York, a younger son of the King, the British struggled to co-operate with their Russian allies and faced unexpectedly heavy French resistance.

[41]: 27 In May 1809 the Secretary of State for War, Lord Castlereagh, offered Chatham the command of an amphibious assault aimed at destroying the French fleet and fortifications around Antwerp and the island of Walcheren.

The army made slow headway and the French immediately withdrew their fleet to Antwerp, a tactic that should have been foreseen by the politicians, admirals and generals planning the campaign from the start.

During these years Arthur Wellesley made a great success of the command that Chatham had turned down, leading Allied forces to victory in the Peninsular War and invading southern France.

Rewarded with a Dukedom, he became Britain's premier military commander and oversaw the Allied victory at the Battle of Waterloo in 1815, with Chatham playing no part in any of these campaigns.

[1] His predecessor, the father of the future Queen Victoria, had not been on the Rock since a mutiny amongst his troops in 1803 and a series of acting Governors had performed duties on his behalf.

Chatham initially intended to also hold the post in absence, but following political pressure from the opposition he agreed to take personal command in Gibraltar.

Sir George Don, who had been acting command of the garrison for seven years, continued to serve as lieutenant governor under Chatham, and the two men enjoyed a good relationship.

[48] He took over his post at a time when neighbouring Spain was undergoing severe turbulence as Ferdinand VII was challenged by Spanish Liberal opponents.