Last August, Leslie Gelb, the former diplomat, New York Times columnist, and influential foreign-policy thinker, passed away. Les had been on Democracy’s editorial board since its founding in 2007, and was a constant source of guidance and support. As the journal’s founder Andrei Cherny put it “He was not only a giant, he was a mensch.” In this collection of remembrances, Les’s students, friends, and colleagues explain who he was, and what lessons he can still teach us.