By 1792, slave rebels controlled a third of the island. The success of the slave rebellion caused the newly elected Legislative Assembly in France to realize it was facing an ominous situation. To protect France’s economic interests, the Assembly granted civil and political rights to free men of colour in the colonies in March 1792. Countries throughout Europe, as well as the United States, were shocked by the decision, but the Assembly was determined to stop the revolt. Apart from granting rights to the free people of colour, the Assembly dispatched 6,000 French soldiers to the island. The new governor sent by Paris, Léger-Félicité Sonthonax was a supporter of the French Revolution who abolished slavery in the Northern Province of Saint Domingue and had hostile relations with the planters, whom he saw as royalists.

Meanwhile, in 1793, France declared war on Great Britain. The white planters in Saint Domingue, unhappy with Sonthonax made agreements with Great Britain to declare British sovereignty over the colony, believing that the British would maintain slavery. The British Prime Minister, William Pitt the Younger believed that the success of the slave revolt in Saint Domingue would inspire slave revolts in the British Caribbean colonies and that taking Saint Domingue, the richest of the French colonies would be a most useful bargaining chip to have when the peace negotiations began to end the war, and in the interim, occupying Saint Domingue would mean bringing all of its great wealth into the British treasury. The American journalist James Perry noted that the great irony of the British campaign in Haiti was instead of being the great money-spinner as expected, the campaign ended in a complete debacle that cost the British treasury millions of pounds and the British military thousands upon thousands of dead, all for nothing. Spain, who controlled the rest of the island of Hispaniola, would also join the conflict and fight with Great Britain against France. The Spanish forces invaded Saint Domingue and were joined by the slave forces. For most of the conflict, the British and Spanish supplied the rebels with food, ammunition, arms, medicine, naval support, and military advisors. By August 1793, there were only 3,500 French soldiers on the island. On 20 September 1793, about 600 British soldiers from Jamaica landed at Jérémie to be greeted with shouts of “Vivent Les Anglais! from the French population. On 22 September 1793, Mole St. Nicolas, the main French naval base in Saint Domingue surrendered to the Royal Navy peacefully. Everywhere, the British went, they restored slavery, which made them especially hated by the Haitians. To prevent military disaster, and secure the colony for republican France as opposed to Britain, Spain, and French royalists, separately or in combination, the French commissioners Léger-Félicité Sonthonax and Étienne Polverel freed the slaves in St. Domingue.

The decision was confirmed and extended by the National Convention, the first elected Assembly of the First Republic (1792–1804), on the 4th of February 1794, under the leadership of Maximilien Robespierre. It abolished slavery by law in France and all its colonies and granted civil and political rights to all black men in the colonies. The French constitutions of 1793 and 1795 both included the abolition of slavery. The constitution of 1793 was never applied, but that of 1795 was implemented and lasted until replaced by the consular and imperial constitutions under Napoleon Bonaparte. Despite racial tensions in Saint Domingue, the French revolutionary government at the time welcomed abolition with a show of idealism and optimism. The emancipation of slaves was viewed as an example of liberty for other countries, much as the American Revolution was meant to serve as the first of many liberation movements. Danton, one of the Frenchmen present at the meeting of the National Convention, expressed this sentiment:

“representatives of the French people, until now our decrees of liberty have been selfish, and only for ourselves. But today we proclaim it to the universe, and generations to come will glory in this decree; we are proclaiming universal liberty…We are working for future generations; let us launch liberty into the colonies; the English are dead, today.”

In nationalistic terms, the abolition of slavery also served as a moral triumph of France over England as seen in the latter half of the above quote. Yet the abolition of slavery did not allow for independence and did not persuade Toussaint Louverture until some time later to stop working with the Spanish army.

The British force that landed in St. Domingue in 1793 was too small to conquer the place, being only capable of holding only few coastal enclaves, much to the disappointment of the French planters, who had been expecting more and to the relief of Sonthonax, who twice refused ultimatums from Commodore John Ford to surrender Port-au-Prince. In the meantime, a Spanish force under Captain-General Joaquin Garcia y Moreno had marched into the Northern Province. Toussaint Louverture, the ablest of the Haitian generals had joined the Spanish, accepting an officer’s commission in the Spanish Army and being made a knight in the Order of St. Isabella. The main British force for the conquest of St. Domingue under General Charles Grey aka “No-flint Grey” and Admiral Sir John Jervis set sail from Portsmouth on 26 November 1793, which was in defiance of the well known rule that the only time that one could campaign in the West Indies was from September to November, when the mosquitoes that carried malaria and yellow fever were scarce. After arriving in the West Indies in February 1794, Grey chose to conquer Martinique, St. Lucia and Guadeloupe and troops from his force under the command of John Whyte only arrived in St. Domingue on 19 May 1794. Whyte decided rather attacking the main French bases at Le Cap and Port-de-Paix to march towards Port-au-Prince, whose harbour was reported to have 45 ships loaded with sugar as the allure of rich booty proved more enticing. Whyte took Port-au-Prince, but Sonthonax and the French forces were allowed to leave in exchange for not burning the 45 ships loaded with sugar. By May 1794, the French forces were severed in two by Toussaint with Sonthonax commanding in the north and André Rigaud leading in the south. At this point, Toussaint for reasons that remain obscure suddenly joined the French and turned against the Spanish, ambushing his allies as they emerged from attending mass in a church at San Raphael on 6 May 1794. The Haitians soon expelled the Spanish from St. Domingue. Toussaint, despite being a former slave, proved to be forgiving of the whites, insisting that he merely fighting to assert the rights of the slaves as black French people to be free, did not want independence from France, and urged the surviving whites, including the former slave masters to stay and work with him in rebuilding St. Domingue.

Rigaud had checked the British in the south, taking the town of Léogâne by storm and driving the British back to Port-au-Prince. During the course of 1794, most of the British forces were killed by yellow fever, the dreaded “black vomit” as the British called it, as within two months of arriving in St. Domingue the British had lost 40 officers and 600 men to yellow fever. Ultimately, of Grey’s 7,000 men, about 5,000 were to die of yellow fever while the Royal Navy reported losing “…forty-six masters and eleven hundred men dead, chiefly of yellow fever”. The British historian Sir John Fortescue wrote: “It is probably beneath the mark to say that twelve thousand Englishmen were buried in the West Indies in 1794”. Rigaud failed in an attempt to retake Port-au-Prince, but on Christmas Day 1794, in a surprise attack he stormed and retook Tiburon. The British lost about 300 dead and the French took no prisoners, executing any British soldier and sailor who surrendered. At this point, Pitt decided to reinforce failure by launching what he called “the great push” to conquer St. Domingue and the rest of the French West Indies, sending out the largest expedition Britain had yet mounted in its history, a force of about 30,000 men to be carried in 200 ships. Fortescue wrote that aim of London in the first expedition had been to destroy “the power of France in these pestilent islands…only to discover when it was too late, that they practically destroyed the British army”. By this point, it was well known that service in the West Indies was virtually a death sentence and in Dublin and Cork, soldiers from the 104th, 111th, 105th, and 112th regiments rioted when they learned that they were being sent to St. Domingue. The fleet for the “great push” left Portsmouth on 16 November 1795 and was wrecked by a storm, before sending out again on 9 December.

General Ralph Abercromby, the commander of the forces committed to the “great push” in the West Indies hesitated over which island to attack when he arrived in Barbados on 17 March 1796 before he dispatched a force under Major General Gordon Forbes to Port-au-Prince. Forbes’s attempt to take the French-held city of Leogane ended in disaster as the French had built a deep ditch with palisades while Forbes had neglected to bring along heavy artillery. The French commander, the mulatto General Alexandre Pétionproved to be an excellent artilleryman, who used the guns of his fort to sink two of the three ships-of-line under Admiral Hyde Parker in the harbour, before turning his guns to the British forces; a French sortie led to a British rout and Forbes retreating back to Port-au-Prince. In the meantime, as more and more ships bringing troops committed to the “great push” arrived, more and more soldiers died of yellow fever. By 1 June 1796, of the 1,000 from the Sixty-sixth regiment, only 198 had not been infected with yellow fever and of the 1,000 men of the Sixth-ninth regiment, only 515 were not infected with yellow fever. Abercromby predicated that at the current rate of yellow fever infection, all of the men from the two regiments would be dead by November. Ultimately, 10,000 British soldiers had arrived in Saint Domingue by June, but besides for some skirmishing near Bombarde, the British remained put in Port-au-Prince and other coastal enclaves while yellow fever continued to kill them all off. The government attracted much criticism about the mounting costs of the expedition to St. Domingue in the House of Commons, and in February 1797, General John Graves Simcoe arrived to replace Forbes with orders to pull back the British forces to Port-au-Prince. As the human and financial costs of the expedition mounted, more and more people in Britain demanded a withdrawal from St. Domingue, which was devouring money and soldiers while failing to produce the expected profits.

On 11 April 1797, Colonel Thomas Maitland of the Sixty-second Foot regiment landed in Port-au-Prince, and wrote in a letter to his brother that British forces in St. Domingue had been “annihilated” by the yellow fever. Service in St. Domingue was extremely unpopular in the British Army owing to terrible death toll caused by yellow fever with one British officer writing of his horror of seeing his friends “drowned in their own blood” while “some died raving Mad”. Simcoe used the new British troops to push back the Haitians under Toussaint, but in a counter-offensive, Toussaint and Rigaud stopped the offensive with Toussaint retaking the fortress at Mirebalais. On 7 June 1797, Toussaint attacked Fort Churchill in an assault that was noted for its professionalism as it for its ferocity. Under a storm of artillery, the Haitians placed ladders on the walls and were driven back after four times with heavy losses. Even through Toussaint had been defeated, the British were astonished that Toussaint had turned a group of former slaves with no military experience into troops whose skills were the equal of a European army. In July 1797, Simcoe and Maitland sailed to London to advise a total withdrawal from St. Domingue, a thesis that was so persuasive by this point that in March 1798 Maitland returned with a mandate to withdraw, at least from Port-au-Prince. On 10 May 1798, Maitland met with Toussaint to agree to an armistice, and on 18 May the British had left Port-au-Prince. British morale had collapsed with the news that Toussaint had taken Port-au-Prince, and Maitland decided to abandon all of St. Domingue, writing that the expedition had become such a complete disaster that withdrawal was the only sensible thing to do, even though he did not have the authority to do so. On 31 August, Maitland and Toussaint signed an agreement where in exchange for pulling out all of St. Domingue, Toussaint promised to not support any slave revolts in Jamaica. Between 1793–98, the expedition to St. Domingue had cost the British treasury four million pounds and 100,000 men either dead or crippled from the effects of yellow fever.

After the departure of the British, Toussaint turned his attention to Rigaud. In March 1797, the Directory had unleashed French privateers against American shipping, leading to the Quasi-War between France and the United States with the U.S Navy hunting down the French ships that were taking American merchantmen. Through the United States was hostile towards Toussaint, the U.S. Navy agreed to support the Haitians with the frigate USS General Greene command by Captain Christopher Perry providing fire support to the Haitians as Toussaint laid siege to the city of Jacmel, held by French forces under the command of Rigaud. On 11 March 1800, Toussaint took Jacmel and Rigaud fled on the French schooner La Diana. Through Toussaint maintained he was still loyal to France, to all intents and purposes, he ruled Saint Domingue as its dictator.

It has recently been estimated that the slave rebellion resulted in the death of 350,000 Haitians and 50,000 European troops. According to the Encyclopedia of African American Politics, “Between 1791 and independence in 1804 nearly 200,000 blacks died, as did thousands of mulattoes and as many as 100,000 French and British soldiers.”Yellow fever did most of the killing. Geggus points out that at least 3 out of every 5 British troops sent there in 1791–97 died of disease. There has been considerable debate over whether the number of deaths caused by disease was exaggerated.