"They grabbed what they could get for the sake of what was to be got. It was just robbery with violence, aggravated murder on a great scale, and men going at it blind– as is very proper for those who tackle a darkness. The conquest of the earth, which mostly means the taking it away from those who have a different complexion or slightly flatter noses than ourselves, is not a pretty thing when you look into it too much." ............Marlow in
Conrad, Joseph (2012-11-01). Heart of Darkness (Kindle Locations 103-106). . Kindle Edition.
The sins of empire are easy to catalog, but also easy to exaggerate. Not everything bad that happens to a nation that becomes a colony can be fairly attributed to the colonizers. Plagues and famines happen to free countries as well as colonies. It's also easy to ignore the evils colonialism ended. It was not so long ago that the British found and figured out how to eliminate the most brutal kind of human sacrifice in India. In America, the Spanish ended Aztec power, one of the most brutal regimes we have ever heard of.
The worst fate a conquered people can face is extermination, and the native Americans have been the world's most prominent victims, but they were hardly the first. Their situation is also a bit unusual in that most of the extermination was entirely accidental, because it was old world germs that killed them.
Plunder on massive scale might be number two on the list of calamities, and here again the native Americans of Peru and Mexico were extreme examples.
What about cultural destruction? For me that's the toughest one to weep for. I'm happy that colonial regimes wiped out human sacrifice and a whole lot of other customs I dislike. Cultural destruction is painful for those who lose it, but I think a good case can be made that much of it is being replaced by something better.