This paper discusses the medieval castle and town of Sölvesborg in Blekinge. It was a typical motte and bailey castle consisting of a huge brick tower built on an artificial mound surrounded by an inner moat and a large outer bailey. The castle, which was partly excavated in the 1940s, 1970s and 2010s, functioned as the royal Danish castle that controlled Blekinge in the Middle Ages. It has always been seen as a creation of the Danish Crown. The castle is however located on the inside of the town in relation to the Baltic, which raises questions regarding the relationship between the castle and the town, as does the size of the unusually large bailey that surrounds the motte. It is obvious that the castle could not defend the town from an attack from the sea or from the west. This raises questions about how this spatial pattern emerged and what came first, the castle or the town. The existing archaeological and historical and sources regarding the castle and the town are presented and summarized and new hypotheses regardingthe origin of the castle and the town are presented. Perhaps the intention was that commercial activities originally should have been located inside the bailey, and perhaps the builder was the Swedish king Magnus Eriksson, in the years of Danish dissolution in the 14th century.