Norwegian spring-spawning herring and Northeast Arctic cod are two of the largest and commercially most important fish stocks in the North Atlantic. Both these stocks have their spawning fields along the Norwegian coast and they have been the major target species for Norwegian fisheries for a millennium. They are also among the few fish stocks in the world which have been systematically investigated and monitored for more than a century. The scientific results, arrived at early in the 20th century for these two stocks, formed the basis for much of the development in international fisheries science later on. This book describes how fisheries, fisheries science, and management for Norwegian spring-spawning herring and Northeast Arctic cod developed during the 20th century. Over time, both populations developed serious decline in stock size and yield due to overfishing. The herring stock was in a state of collapse for about 20 years. Management measures that were then introduced permitted both stocks to recover in the 1990s. The contributors to the book have all been working as fisheries scientists at the Institute of Marine Research in Bergen.