It became important as a market town as well. In 1570 Hamar Cathedral in Hamar was burned and Hamarhus castle was destroyed by the Swedish armies during the Seven Years' War with Sweden. Hamar lost its city status, leaving no "kjøpstad", or official market city, between Christiania and Trondheim. Eastern Norway needed an organized market for trading goods. The Grundset market "(Grundsetmart'n)" in Elverum municipality grew to meet the need. It is recorded as existing in the 17th century, and in 1765 the owner of Gaarder obtained special market privileges from the king, to take place six miles north of the population center of Elverum on his estate. By 1767, it was described as Norway's largest and most famous market. In the first week of March, for almost 300 years, the folks of the district met to trade and to celebrate. People from Gudbrandsdal, Oslo, Trøndelag, and Sweden also regularly came to "Grundsetmart'n". The Grundset market was finally abandoned in 1901, when pressures of the railroad and other markets made it superfluous.