The aim of this paper is to analyse the paradigm of Prussian urban and architectural design concepts – particularly it’s impact on building activities in the annexation area in Poznan at the turn of the 19th and 20th centuries. The case study is represented by ephemeral but yet influential architecture of the East German Exhibition (die Ostdeutsche Ausstellung), Imperial Castle and government district. The exhibition was held in 1911 in Poznan (Poland), the capital of Posen Province in former Prussia. The fair and new was an element of Prussian propaganda and Kulturhebung policy – an improvement of cultural and living standards for the benefit of the German population in Poznan. In reference to concepts of Benedict Anderson – back then the population of Poznan could be described as an ‘imagined community’. This study is a new interpretation of the Exhibition considered as an heterotopic accumullation of various styles and the new district as a ‘national-Prussian’ monument fundamentally differing from Polish building environment and cultural heritage. The main focus of this complex issue is laid on the physical and visual as well as virtual representation of the architecture: building plans, photographs and how they had been perceived and later presented in journals, publications and books. This paper examines the depiction of the new architectural patterns in historiography now and hundred years ago, it’s purpose and how it conveyed the changes of political concepts – designating or crossing national boundaries. Simultaneously it approaches the matter of cultural imputation in architectural historiography. As last but not least the presentation investigates if the new patterns in the architecture of the East German Exhibition planted the seed of changes or had added another meaning in the urban space and residential architecture of Poznan.