A protester threw eggs at the UK’s King Charles and Queen Consort at an event in York, screaming “this country was built on the blood of slaves.” The eggs missed their target and the man was restrained by police officers.

Other people in the crowd seemed to condemn the thrower and started chanting “God save the King,” and shouting “shame on you” at the protester. After the man’s arrest, the king went on with a traditional ceremony, in which he was officially welcomed to York by the city’s Lord Mayor.

The British Empire was among the countries that benefited the most during the slave-trading era. It is estimated that Britain transported 3.1 million Africans (of whom only 2.7 million arrived) to its colonies in the Americas and other countries.