Urban history in Scandinavian countries has long been practised mainly in the form of individual town histories, a large number of which have been written by local amateurs. Among professional historians, however, local history (including the history of towns, parishes and regions) has been of interest since the late-nineteenth century, and has been especially popular in Norway and Finland. This may have to do with the fact that these two countries did not become independent until 1905 and 1917 respectively. The Swedish-Norwegian union of 1814–1905 had been preceded by Norway's incorporation into the Danish kingdom from 1536 on, and Finland's inclusion in the Russian empire as a semi-autonomous grand duchy between 1809 and 1917 had been preceded by her incorporation into the Swedish kingdom since the Middle Ages. These facts must be kept in mind in order to realize why historical research in Scandinavia has so many topics and features in common. They also explain some of the differences, such as why historians in Norway and Finland to a greater extent than in Sweden and Denmark should have turned to local history both before and after having achieved independence, in order to strengthen the conciousness of national identity in the two countries. Although there was much interest in rural local history, town history also got its share. There are very few towns – if any – in Norway and Finland that have not had their histories written; in Denmark and Sweden urban and local history also became increasingly popular in the 1920s and 1930s.