Belgium was born late, in 1830, into a Europe that already had colonies. The young constitutional monarchy mostly didn't want them. King Leopold I tested the waters in the 1840s and 1850s — a quiet attempt to buy Cuba from Spain, a doomed contract to colonise the Kingdom of Hawaii, an abortive Belgian settlement at Santo Tomas de Castilla in Guatemala that yellow fever and malaria emptied within a decade. Belgian governments concluded that empire was expensive, risky, and unrewarding compared to the booming industrial trade Belgium already did with South America and Russia. Then Leopold II was crowned. He spent the 1860s and 1870s investigating dozens of potential colonies, found his ministers indifferent, and decided to become a colonial power on his own. He hired the explorer Henry Morton Stanley, founded the International African Association as a humanitarian fig leaf, and at the Berlin Conference of 1884–1885 persuaded the great powers to recognise his personal sovereignty over the Congo Basin as the Congo Free State. There was no Belgian government involved. The Congo was his.

Wild rubber became hugely valuable in the 1890s, when the bicycle craze and then the automobile created demand the world had never seen. Leopold's Free State, with the support of its colonial militia, the Force Publique, divided the Congo into private concessions and imposed rubber quotas on Congolese communities. Companies like the Abir Congo Company met shortfalls with floggings, hostage-taking, village burnings, and the cutting of hands — sometimes from the dead, sometimes from the living — as proof to officers that ammunition had been used on enforcement and not wasted on hunting. Disease killed many more: smallpox introduced by colonial contact killed nearly half the population around the lower Congo River alone. Estimates of total Free State deaths vary because the first census did not happen until 1924; the often-cited figure of ten million, drawn from the work of historian Adam Hochschild, is one of several reasoned estimates. The photographs that eventually surfaced of Congolese victims — including children with severed hands — galvanised an international reform movement led by the Briton E. D. Morel and the Irishman Roger Casement. They were the first global human rights campaign of the twentieth century.

Faced with mounting international condemnation, Belgium reluctantly took the colony off its king's hands in 1908. The new Belgian Congo replaced personal rule with what the administration called a colonial trinity of state, missionary, and corporate interest. Brutality on the Free State scale ended; structural racism, forced labour for public works, and rigid segregation continued. Congolese troops served Belgium in both world wars — most strikingly in the East African Campaign of World War II, where they helped force the Italian surrender at Saio. In the 1940s and 1950s Belgian planners spoke of making the Congo a model colony, building cities and infrastructure at a pace that produced a Europeanised African middle class the colonisers called the evolues. But political rights did not follow. When the Congo achieved independence in 1960 as the Republic of Congo-Leopoldville, under Patrice Lumumba and Joseph Kasa-Vubu, the country had only a handful of African university graduates and almost no Congolese in senior administrative posts. The Cold War broke over the new state within weeks. Lumumba was assassinated in early 1961 with Belgian and American complicity in the planning, his body dissolved in acid, a single gold-capped tooth eventually preserved. Belgium officially returned that tooth to his family in 2022.

After the First World War, Belgium was awarded a League of Nations mandate over Ruanda-Urundi — the former German colonies that became modern Rwanda and Burundi. The Belgian administration inherited the German policy of ruling through Tutsi aristocrats and made it sharper, eventually issuing ethnic identity cards that hardened the distinction between Hutu and Tutsi into a bureaucratic certainty. Independence came in 1962. The identity cards remained in use in Rwanda; thirty-two years later, during the 1994 genocide, they would determine who lived and who died at the roadblocks. Belgium also held the Lado Enclave on the upper Nile from 1894 until Leopold's death in 1910, the tiny Belgian concession of Tianjin in China from 1900 until 1931, and a co-administrator's seat in the Tangier International Zone in Morocco. None of these compared in scale or consequence to what happened in the Congo Basin.

For most of the twentieth century, Belgium did not talk much about any of this. The Royal Museum for Central Africa in Tervuren, on Brussels' eastern edge, displayed colonial trophies in the spirit of the era that had taken them. Then, slowly — through the work of Congolese activists in Brussels, of historians like Hochschild and Daniel Vangroenweghe, and of young Belgians who came of age after the millennium — the silence began to break. The Tervuren museum was renovated and reopened in 2018 with its colonial framing reinterpreted, though the renovation was itself criticised as insufficient. In 2020, after George Floyd's killing reverberated worldwide, statues of Leopold II were vandalised, removed, or quietly relocated in several Belgian cities. King Philippe expressed deep regret to the Congolese people in 2020 and again on a visit to Kinshasa in 2022. The tooth of Patrice Lumumba came home. The conversation has not ended. It has not even fully begun.