The word genocide was coined in 1944 by a Polish lawyer named Raphael Lemkin, who lost 49 members of his Jewish family in the Holocaust.

But it wasn’t the Nazis who first got him thinking about how to stop the intentional destruction of national, ethnic or religious groups. Decades earlier, when he was in college, he heard about the assassination of Talaat Pasha, one of the main organizers of the deportation and mass killing of Armenians in the Ottoman Empire, by an Armenian man who had survived it. The subsequent trial of the assassin opened his eyes to the suffering of the Armenian people.

“At that moment,” Lemkin wrote later in his autobiography, “my worries about the murder of the innocent became more meaningful to me. I didn’t know all the answers, but I felt that a law against this type of racial or religious murder must be adopted by the world.”

The Ottoman Empire killed an estimated 1.5 million Armenians during World War I. On Saturday, President Biden called it “genocide,” making him the first president to do so since Ronald Reagan. It’s a move that could further strain relations with U.S. ally Turkey.

On April 24, Armenians laid flowers at the country's memorial to the victims of massacres, deportations and forced marches under the rule of Ottoman Turkey. (Jonathan Baran/AP)

The Ottoman Empire comprised many different ethnic and religious groups but was largely controlled by Muslims. In 1908, a group called the Young Turks seized control, first of a society called the Committee of Union and Progress, and then of the government. The CUP promised modernization, prosperity and secular, constitutional reforms.

At first, it seemed as though this vision included ethnic Armenians, most of whom were poor peasants on the eastern side of Anatolia (what is now Turkey). But over the next few years, the CUP grew increasingly focused on Turkish nationalism; by 1913, it was a full-on dictatorship.

When World War I broke out, Armenians found themselves physically on both sides of the battlefront between the Ottomans and the Russians. The Ottoman government drafted Armenian men to fight, but when the military suffered heavy losses, it blamed them on Armenians, accusing them of collaborating with the enemy. The Armenian soldiers were disarmed and murdered by Ottoman troops.

On April 24, 1915, the government arrested about 250 Armenian leaders and intellectuals. This is seen by many as the beginning of the massacre, and April 24 now marks Armenian Genocide Remembrance Day.

In the following months, most of those Armenian leaders were killed. The military forced Armenian villagers from their homes and on long, cruel marches to concentrations camps in what is now northern Syria and Iraq. Many of them died along the way; others died in the camps of starvation and thirst. Meanwhile, irregular forces and locals rounded up Armenians in their villages and slaughtered them. Historians estimate that between 600,000 and 1.5 million Armenians died.

The few survivors were often forced to convert to Islam, and Armenian orphans were adopted by Muslim families. The empty homes and businesses were also given to Muslims, some of whom had recently been forced out of the Balkans.

At this point in the war, the United States was still neutral. Henry Morgenthau Sr. was the U.S. ambassador to the Ottoman Empire and witnessed many of the atrocities. In a July 16, 1915, cable, he told the State Department: “It appears that a campaign of race extermination is in progress.”

He pleaded with Ottoman officials to stop it, and with President Woodrow Wilson to intervene. (He didn’t.) Eventually, Morgenthau fundraised for Armenian refugees and published a book recounting the horrors he had witnessed.

The Republic of Turkey rose from the ashes of the Ottoman Empire after World War I, led by its founder, Mustafa Kemal Ataturk, who had been part of the Young Turks takeover and a revered general. Ataturk brought the long-promised secular reforms and modernization, though, by that time, the country he united was missing millions of its ethnic Armenians, Assyrians and Greeks.

Nations often resist exploring the darkest corners of their past. Many Americans, for example, are angered by the characterization of the nation’s founders as enslavers of Africans and killers of Indigenous people. Former president Donald Trump even tried to introduce a new history curriculum to paper over some of the uglier chapters of our history.

But in Turkey, that avoidance is enshrined into law; publicly denigrating “Turkishness” is punishable by six months to two years in prison.

Some of Turkey’s most well-known authors and journalists have been prosecuted under this law just for acknowledging the mass killings of Armenians in 1915. Turkish officials have acknowledged that atrocities took place, but they regard it more as a civil war than a coordinated campaign to destroy the Armenian people.

So was it a genocide? The majority of historians say yes.

As did the man who created the very word “genocide.”

Correction: A previous version of this article misstated the first name of the Polish lawyer. He is Raphael Lemkin, not Rafael Lemkin. The article has been corrected.

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