This volume contains the invited papers presented at the NATO Advanced Research Workshop on the Theory of Sunspots, held in Cambridge, England, 22-27 September 1991. The idea of holding this Workshop first arose during the Solar Optical Telescope work shop on Theoretical Problems in High-Resolution Solar Physics in Munich in 1985. At that meeting, separate discussion groups were formed to consider specific topics in solar physics. The discussion group on sunspots recommended that there be a meeting devoted to theoretical problems associated with sunspots, the motivation being the consensus...