Harderwijk received city rights from Count Otto II of Guelders in 1231. A defensive wall surrounding the city was completed by the end of that century. The oldest part of the city is near where the streets Hoogstraat and Grote Poortstraat are today. Around 1315 the city was expanded southwards, which included the construction of what is now called the Grote Kerk (Large Church). A second, northward expansion took place around 1425. Particularly along the west side of town much of the wall still exists, although often not in entirely original form. This also goes for the only remaining city gate, the picturesque Vischpoort.
Harderwijk was a member of the Hanseatic League. It lies on what used to be the Zuider Zee shore (Southern Sea, now the IJsselmeer) and consequently its economy was strongly based on fishing and seafaring in general. This dramatically changed after 1932, when the Zuiderzee was cut off from the North Sea for safety reasons. Because of this, there are few fishing boats remaining in the harbour these days, which is now mainly home to yachts. An annual event illustrating the former importantance of the fishing industry to Harderwijk is Aaltjesdag, which translates to Eel day. Fish can still be bought at stands and restaurants on the boulevard throughout the year except for the winter months. Tourists are common customers, while local people no longer make their living from the fisheries.