The German parliament on Thursday defied pressure from Turkey, voting to recognize the massacre of 1.5 million Armenians in 1915 as a genocide.
The Armenian Genocide was carried out by Muslim Ottoman Turkish troops, who embarked on a systematic campaign during the First World War to annihilate the Armenian Christian minority via atrocities including mass starvation, death marches and mass-executions.
Turkey rejects the term "genocide" in the Armenian context, denying - despite the evidence - that a mass-slaughter of Armenians took place.
Ankara had lobbied hard to convince German MPs to vote against the motion, with Turkish Prime Minister Binali Yildirim slamming it as "irrational" for Germany to recognize the genocide.
Turkish President Recep Tayyip Erdogan also phoned German Chancellor Angela Merkel personally, and warned that ties between the two countries would deteriorate "if (Germany) falls into such a game."
Germany and the wider European Union have turned to Turkey to stem the enormous flow of refugees from Syria and Iraq into Europe, and Ankara only recently agreed to a deal to take back scores of migrants - making the timing of the vote extremely sensitive.
But the motion passed nonetheless, with many Armenian leaders present at the parliament lauding the historic vote.
Germany was at the time a strategic ally of the Ottomans, and many historians have noted its compliance indirectly enabled the slaughter.
Decades later, Adolf Hitler cited the way the world had "forgotten" the Armenian Genocide as proof he would get away with annihilating the Jewish people.