The Dutch royal house benefited from the Netherlands’ colonial policies for centuries and helped the country’s slave trade survive, an in-depth historical study commissioned by King Willem-Alexander concluded on Friday.
Historians and human rights experts at Leiden University spent three years on the inquiry, which covered the period from 1600 to the present. The House of Orange-Nassau “actively supported Dutch colonialism for centuries, but only rarely determined colonial policy,” the university said in a statement. The researchers’ own verdict went further. “The involvement of the House of Orange-Nassau was wholehearted and without any real reservations,” they concluded, according to a Reuters report.
The family also made money. It earned an estimated 576 million euros from slavery, most of it in the former Dutch East Indies, the website DutchNews.nl reported. For the study, the king opened the royal archives.
“All stadtholders, kings, and queens, at least up to and including Wilhelmina, were convinced of the legitimacy of colonialism and its importance for the Netherlands,” the lead researcher said, according to DutchNews.
Willem-Alexander ordered the inquiry himself and paid for it, according to Leiden’s description of the project, which says the work runs from 2023 to 2026 and closes with the publication of five books. He had already apologized for the country’s role in slavery. At a July 2023 commemoration in Amsterdam marking the abolition anniversary, he told the crowd, “I ask forgiveness for this crime against humanity,” The Guardian reported.

