Love this bit from French Historian Paul Fregosi about the French colony of Saint Domingue, before the outbreak of the revolution that established Haiti:
Whites, mulattos and blacks loathed each other. The poor whites couldn't stand the rich whites, the rich whites despised the poor whites, the middle-class whites were jealous of the aristocratic whites, the whites born in France looked down upon the locally born whites, mulattoes envied the whites, despised the blacks and were despised by the whites; free Negroes brutalized those who were still slaves, Haitian born blacks regarded those from Africa as savages. Everyone—quite rightly—lived in terror of everyone else. ...Haiti was hell.
It endured because of the profits earned by growing sugar and coffee, which made Haiti by the numbers one of the richest places in the world and the source of most of the profit France earned from its colonies.
The sugar islands of the Caribbean were one of the most brutal human societies I know of, an empire of suffering. Because of disease and the brutal conditions life expectancies were short for everyone, even the rich whites. Violence was constant: revolts by the enslaved, raids by maroons who built villages in the mountains, and savage retaliation by the whites against both, to which one must add constant low-level war among the colonial powers and, when war was not official, a plague of piracy. As Fregosi says, the whole society was characterized from top to bottom by mutual loathing and a savage contest for social superiority.
The Haitian revolution of 1791 was a bloodbath; best estimates are that at least 20,000 were killed in just the first year. But it went on and on, with intervention by warring European states, scorched earth tactics that destroyed vital infrastructure, division among the black rebels, etc., etc., (One episode of conflict among the black rebels is known as the War of Knives.) It was not until 1801 that Toussaint Louverture was sufficiently in control to issue a constitution for an independent Haiti, inaugurating a great Latin American tradition by proclaiming himself President for Life. AND THEN in 1802 Napoleon sent a strong force to recapture the island, which led to two more years of war before the Haitians, with British help, finally defeated the French. Obviously records of this period are not great, but historians estimate that by 1805, 400,000 people may have died. The Haitians celebrated their victory by massacring most of the surviving whites on the island, to the total of about 5,000.
The state that emerged after the revolution banned slavery but was far from just and equal; the French-speaking, mixed-race elite completely controlled the island for the next century, treating the patois-speaking blacks with contempt. The European powers effectively cut off trade to Haiti, which kept their economy from ever recovering, so that from one of the richest place in the world in 1790 it became one of the poorest.
All in all it is a great illustration of where brutality leads when pushed to its limits: evil follows hard upon evil, and we reap what we sow.