Christopher Wolfgang John Alexander (1936–2022) was an Austrian-born British-American architect and design theorist. He was an emeritus professor at the University of California, Berkeley. His theories about the nature of human-centered design have affected fields beyond architecture, including urban design, software, and sociology. Alexander designed and personally built over 100 buildings, both as an architect and a general contractor. Alexander is best known for his 1977 book A Pattern Language, a perennial seller some four decades after publication. Reasoning that users are more sensitive to their needs than any architect could be, he collaborated with his students Sara Ishikawa, Murray Silverstein, Max Jacobson, Ingrid King, and Shlomo Angel to produce a pattern language that would empower anyone to design and build at any scale. His other books include Notes on the Synthesis of Form, A City is Not a Tree, The Timeless Way of Building, A New Theory of Urban Design, and The Oregon Experiment. More recently he published the four-volume The Nature of Order: An Essay on the Art of Building and the Nature of the Universe, about his newer theories of “morphogenetic” processes, and The Battle for the Life and Beauty of the Earth, about the implementation of his theories in a large building project in Japan.