W artykule zaprezentowano metodykę kompleksowego, interdyscyplinarnego podejścia do badania dawnych planów. Podejście to zastosowano do analizy i oceny najstarszego planu Lublina - interesującego dokumentu kartograficznego i ważnego materiału historycznego o znaczeniu ponadregionalnym.
Maps of the past are the focus of interest of many groups of specialists; therefore various methodologies. Complex approaches which combine mathematic-cartographical (numerical) and historical (descriptive) methods are rare. The article presents such an approach to the oldest plan of the entire city of Lublin. Plan de la ville et fauxbourgs de Lublin is linked to the events of Tarnogrod confederation, which makes it a historical document of more than regional significance. The hand drawn document dated 1716 is authored by d'Orken, possibly a military engineer. The first stage was the evaluation of the plan of Lublin as a historic cartographical item. The applied criteria included: mathematical base, legend, range of contents, graphic solutions, use of color, lettering, technical quality and composition. Two of the plan's features are especially noteworthy. First, its contents go beyond a typical general information plan - a large number of elements referring to the negotiations of Tarnogrod confederation make it more of a 'thematic' plan. Second important feature is the application of innovative linear hachures to present relief and abandoning the use of perspective. The second stage was the analysis of plan's contents. At this stage the interdisciplinary character of complex research in the field of history of cartography became evident. As a result a number of controversies concerning interrelations of various objects within the city in the early 18th century were solved. Also, some thematic contents were researched for the first time ever. The final stage was the cartometry analysis of the plan. At first a number of points were selected, which could be recognized in the plan and assigned to the points in today's city. These 30 points created a base for a metering network which made it possible to calculate average local scales, distances, areas, locations and angles (fig. 5-10). These analyses established a number of zones of similar distortion. The least distorted ones are located in the center of the plan, where most of the contents can be found. The most distorted area is in the eastern part of the plan, which was unimportant for its users taking part in the negotiations of Tarnogrod confederation.