His early work centered on effective field theories for hadrons, especially the interactions connecting pions and kaons with protons and neutrons. His 1969 papers with Sidney Coleman, Curtis Callan, and Zumino detailed the mathematical structure of theories with spontaneously broken symmetries. The papers laid much of the foundation for phenomenological hadron physics, but they have had even wider application. They are still being cited today. Wess’s most highly cited work is the 1971 paper with Zumino on anomalies in effective field theories. Anomalies occur when quantum effects violate classical symmetries, giving rise to physical phenomena such as the decay of a neutral pion into two photons. Wess and Zumino showed that anomalous terms in effective Lagrangians must obey certain consistency relations. Those conditions are so important that the terms are now named after them. Despite the fame of that early work, Wess will always be known for the 1974 papers in which he and Zumino constructed the first renormalizable supersymmetric quantum field theory in four dimensions and exhibited its nonrenormalization properties at one loop. Their work ignited an explosion of interest in supersymmetry, a concept that has come to dominate much of modern theoretical physics. His textbook on supersymmetry, with one of us (Bagger), is still a standard reference after 25 years.