BRUSSELS — Belgium's King Philippe on Tuesday expressed regret for his nation's — and his ancestor's — brutal colonization of Congo, a major acknowledgment of history in a country that has long avoided a full reckoning over its relationship with its former colony.

It was the first time a Belgian monarch has edged toward an apology for the colonial rule of what is now the Democratic Republic of the Congo, which is celebrating its 60th anniversary of independence from Belgium on Tuesday. A Black Lives Matter protest that drew 10,000 people to the center of Brussels in early June has helped spark a broader accounting in Belgium over race and colonization, with the country’s Parliament resolving to appoint a truth and reconciliation commission to examine the past.

“At the time of the Congo Free State, acts of violence and cruelty were committed that still weigh on our collective memory. The colonial period that followed also caused suffering and humiliation,” the king wrote in a letter to Congolese President Félix Tshisekedi. “I would like to express my deepest regrets for these injuries of the past, the pain of which is now given new life by the discrimination still too present in our societies.”

The king stopped short of a formal apology, Belgian lawmakers said, because that is considered a political act that can be authorized only by the government under the rules of the country’s constitutional monarchy.

“I believe it necessary that our common history with Belgium and its people should be told to our children in the Democratic Republic of Congo as well as those in Belgium on the basis of scientific work done by the historians of the two countries,” Tshisekedi said Monday in a televised address. “The most important thing for the future is to build harmonious relations with Belgium, because beyond the stigma of history, the two peoples have been able to build a strong relationship.”

King Léopold II, Philippe’s great-great-great uncle, took the Belgian Congo as his personal property in 1885 as European nations staked their colonial claims. His rule was so violent, even by the standards of the era, that a public outcry ensued and forced him to hand control to the Belgian state in 1908. Historians say millions of Congolese died during Belgian rule. Philippe did not refer to Léopold by name in his letter.

Belgian royals have long been silent on the subject of the colonial past, and King Baudouin, who reigned at the time of Congolese independence in 1960, even praised Léopold’s “tenacious courage” in developing the country.

Léopold acted “not as a conqueror but as a civilizer,” Baudouin said in a speech at a 1960 independence ceremony in Congo, expressing sentiments still echoed by some Belgians.

“We are happy to have given the Congo, despite the greatest difficulties, the essential elements for the reinforcement of a country on the road to development,” Baudouin said at the ceremony in the city named after his ancestor, Léopoldville, which is now Kinshasa.

Belgian authorities handed power to Patrice Lumumba, Congo’s first democratically elected prime minister, who was assassinated the following year by Congolese rebels and Belgian army officers acting in coordination with the CIA.

Philippe, who was born 2½ months before Congolese independence, has been silent about the past. Unlike his predecessors — and many older Belgians — he has never visited Congo. Until the coronavirus pandemic, he had been planning to travel there for the observances on Tuesday, which Tshisekedi has designated a day of “meditation,” not celebration.

The king’s letter contrasted with recent comments from his younger brother, Prince Laurent, who said he did not see how Léopold could have caused Congolese suffering because he had never personally stepped foot in the territory.

“It is a turning point insofar as the highest authority in our country is making the link between colonial history and the consequences of this history in our society today, with the discrimination and racism that many people suffer,” Kalvin Soiresse, a Togo-born regional lawmaker in Brussels, told Belgium’s RTBF broadcaster in response to the king’s letter.

Inspired by the U.S. protests that erupted after the police killing of George Floyd in Minneapolis, Belgian activists demanded that their country’s many statues of Léopold be pulled down by Tuesday. Only a handful have come down officially, and there was another protest Tuesday afternoon at the site of one of the biggest statues of Léopold, on a horse, just outside the wrought-iron fence of the main royal palace in central Brussels. But Belgian lawmakers have promised that Léopold’s legacy will be part of discussions scheduled to start in the fall.

One of the organizers of the protests said Tuesday that Philippe’s letter was a start but that much more needed to happen in Belgium before protesters’ demands would be satisfied.

“It is something that opens the window a little bit more; it’s something that makes it a little bit more possible to discuss,” said Joëlle Sambi Nzeba, a protest organizer with the Belgian Network for Black Lives, who grew up between Congo and Belgium. “But for us, it’s not enough to say, ‘Yeah, we regret.’ We don’t want regrets; we want apologies from the royal family and the government.”

Sambi Nzeba said words were only a start: “We need to work on these things together. It’s not enough to apologize. We want reparations, we want to pull down the statues, change the schoolbooks, have more black and brown faces in media and politics.” And she said there was a direct line between the unacknowledged colonial history and present-day racism in Belgium.

Quentin Ariès in Brussels and Max Bearak in Nairobi contributed to this report.