If the history of the western moral imagination is the story of an enduring and unending revolt against human cruelty, there are few more consequential figures than Raphael Lemkin—and few whose achievements have been more ignored by the general public. It was he who coined the word “genocide.” He was also its victim. Forty-nine members of Lemkin’s family, including his mother and father, were rounded up in eastern Poland and gassed in Treblinka in 1943. Lemkin escaped to America, and in wartime Washington gave a name to Hitler’s crimes in his monumental study of the jurisprudence of Nazi occupation, Axis Rule in Occupied Europe, published in 1944. He understood, earlier than almost anybody, that genocide was the darker purpose of Hitler’s war: “genocide is a new technique of occupation aimed at winning the peace even though the war itself is lost.” After the war, thanks largely to his efforts, the United Nations approved the Genocide Convention, and thanks to his crusade a sufficient number of states had ratified the convention by the early 1950s for it to enter into force. He never lived to see a conviction for the crime he was the first to name.

Lemkin’s campaign to promote the convention became an all-consuming obsession: he left adjunct posts at Yale and New York University, neglected himself, forgot to pay his rent, was evicted, went without food while spending all his days lobbying, cajoling, and brow-beating diplomats, politicians, public figures, and newspapermen about genocide. Unfinished fragments of autobiography poignantly document his decline:

As I am devoting all my time to the Genocide Convention, I have no time to take a paying job, and consequently suffer fierce privations.... Poverty and starvation. My health deteriorates. Living in hotels and furnished rooms. Destruction of my clothes. Increased number of ratifications.... The labors of Sisyphus. I work in isolation, which protects me.

He collapsed at a bus stop on 42nd Street in New York in August 1959 and died at the age of 59, friendless, penniless, and alone, leaving behind a bare rented room, some clothes, and a chaos of unsorted papers....