Displaying planning knowledge: early twentieth-century expositions and the transnational influence on Swedish city planning

City planning expositions in the early twentieth century played a significant role in shaping urban policy across Europe, including Sweden. Events such as the St & auml;dtebau Exhibitions in Dresden (1903) and Berlin (1910), and the London Town Planning Conference (1910), became key arenas for the circulation of planning ideas. These forums enabled a two-way exchange of knowledge: Swedish delegates absorbed international models while also presenting domestic planning approaches and legislative frameworks that drew interest abroad. This exchange helped position Sweden not merely as a recipient but as an active contributor to transnational city planning debates. Architect Per O. Hallman was among the Swedish delegates who actively participated in these expositions. Although his role has received little attention in international planning historiography, his involvement reflects how Swedish planners engaged in a wider transnational dialogue. Drawing on underexplored archival sources, including Hallman's correspondence with figures such as Reinhard Baumeister, Josef St & uuml;bben, Theodor Goecke, and Raymond Unwin, this article traces how international exhibitions supported the circulation of planning knowledge. It argues that Sweden's engagement in these forums reflected and contributed to broader international planning debates, which helped align national planning approaches with emerging European developments.