455 BCE - Horton hears a Who and agrees with other animals to boil them in Beezle-nut oil. All die instantaneously except Keith Moon, who had already set himself on fire.
50 CE - The Roman Empire invests in a program where Christians die for their own entertainment. Today, this program is known as Pay-Per-View.
1783 - America wins its war for independence. It agrees to continue the British policy of deindianization.
1525 - Cortéz kills all the dirty Aztecs and purifies Mexico by ordering his men to rape the Aztec women. All are thankful.
1555 - After 18 months of siege, Siena surrenders to the Imperial army. The Republic of Siena is incorporated into the Grand Douche of The Dark Side. Italians begin tanning and fist pump their way to the coastal United States.
1992 - While not really genocide related, Rodney King is found not guilty of beating two white policemen.
1994 - The Rwandan genocide begins. Tutsis and Tootsie Rolls alike are mass exterminated.
2005 - In a World of Warcraft incident, several mages perform an online funeral for their friend who died IRL. During the ceremony, they are interrupted and all are killed by a ruthless clan in a genocide-style extermination.
2022 - The Americans decide to conquer and exterminate their not-so-friendly neighbors to the North, the Canadians.