Gerhart Moritz Riegner was born on September 12, 1911, in Berlin, Germany, into a Jewish family, navigating a dual German-Jewish identity during his upbringing. He pursued legal studies at the University of Heidelberg, the University of Paris, and the Graduate Institute of International Studies in Geneva. Following the Nazi rise to power in 1933, Riegner, who had become a young magistrate, was expelled from the judiciary due to antisemitic decrees banning Jews from such positions. He fled to France briefly before settling in Switzerland, where he joined the World Jewish Congress (WJC) as its representative in Geneva around 1938. A Swiss lawyer and WJC secretary-general from 1940 to 1964 (with some records indicating continued service until 1983), Riegner gained international recognition for the Riegner Telegram of August 1942, which he sent to Allied diplomats, providing one of the first credible alerts about the Nazi plan for the systematic extermination of Europe's Jews—the Holocaust. His work focused on Jewish rescue efforts during World War II and postwar advocacy, extending to philosophical and theological pursuits. He became a key figure in Jewish-Catholic dialogue, earning recognition from Pope John Paul II as a Knight Commander of the Order of St. Gregory the Great and the Nahum Goldmann Medal. Riegner continued his activism and writing into later years, including as an autobiographer. He held nationalities from Germany, France, and Switzerland, reflecting his migratory life amid persecution. He passed away on December 3, 2001.