Living memory exactly!, if we delve back deeply into history, where would you stop? every invading force, The Romans, Genghis Khan, the Mongolian hordes, the Vikings. All would have been responsible for subjugation of the indigenous populations, executions and slavery that was the nature of a conquering force. Masses of people suffered all the time, I don't see anyone on this thread denying those horrors whether they were at the hands of Christians, colonialists, or saying the lives of whoever those people were didn't matter, or whether they believe invaders, Christian or otherwise, had righteousness or God on their side. Events such as the Crusades were just too steeped in the mists of time to create a strong emotional connection.
Recent history has a resonance. Posters have been talking about pretty up to date events, for example those who suffered when Isis set up their de facto headquarters in Raqqah, Iraq and used barbaric methods of torture and execution, the very terrors that belonged to those bygone eras. Every genocide that has happened in the 20th century numerous, the slaughter of Armenians by Turks in the early part of the last century. The Holocaust, Pol Pot in Cambodia, the mass killings of those by Stalin and Mao, Rwanda, Bosnia. Not to mention what's going on right now, the mass murders of young people in Iran just one example.