The monarchy wasn’t a force for good during the age of colonialism/empire, nor is it a force for good now.
In 1660, the Royal African Company was established by the Duke of York, who later became James II, with involvement from his brother, Charles II. The Royal African Company was prolific within the slave trade; according to the Slave Voyages website, between 1672 and 1731 the Royal African Company transported more than 187,000 slaves from Africa to English colonies in North, Central and South America. Many of the enslaved Africans transported by the Royal African Company were branded “DY”, standing for Duke of York.
Source: What are the British monarchy’s historical links to slavery? | The Guardian
Between 1690 and 1807, an estimated 6 million enslaved Africans were transported from west Africa to the Americas on British or Anglo-American ships. The slave trade was protected by the royal family and parliament.