EN
Teutonic Knights had emerged in Chełmno Land in 1226 and immediately subdivided it in some internal administrative units. This also concerned the Rogozno Commandity. It is possible that these territorial and administrative changes were caused by environmental factors. The research on this problem begun with gathering of historical and present-day maps completelly covering territory analysed (circa 280 km²): Schrotter's Map 1798-1803, present-day maps: of soil quality, topographic ones and maps of archaeological revelations. The first step of analysis was to reconstruct the elements of historical landscape for every commandity. Recent and mediaeval landscapes were compared with-each other to trace the differences in earial extent of forests and swamps as well as hydrological setting elements that could be detected. Further, there was estimated the corn production for this territory, by the use of present-day soil quality maps. A soil quality factor was multiplied by an average of corn produciton in mediaeval time and by the areas of commandities, to know how much corn was possible to get from every commandity. Also the approximate number of citizens in this commandity was assesed. The Population density of this territory equaled 12 persons per 1 km², that is about 30% more than in adjacents commandities. This may indicate that in this area the potential of agricultural production was raised in comparison to other administrative units. In those units enviromental conditions allowed to gain 25% of crops more than the inhabitants needed, so initial thesis of historians that changes were caused by insufficient environmental conditions, was not reasonable. the situation was Probably different – those states were self-sufficient, fertile and rich enough to be an object of rivalry.