Arno Mayer, a professor of European history whose work was tied to personal experience, died Dec. 17 at age 97. Mayer joined Princeton’s faculty in 1961 and wrote extensively about European politics and diplomacy after World War I and the rise of Nazism in Germany, which had sparked his Jewish family’s emigration from Luxembourg. After he retired in 1993, Mayer was recognized for his World War II service as one of the U.S. Army’s Ritchie Boys, European-born soldiers trained in counterintelligence. He spoke about the experience for an episode of the public radio show This American Life and a Netflix documentary, Camp Confidential. In 2022, he represented the Ritchie Boys when they received the Elie Wiesel Award, the U.S. Holocaust Memorial Museum’s highest honor. One of Mayer’s former students, Gen. Mark Milley ’80, delivered the keynote.