The abundance of sources on the late medieval feudal system offers great potential for research. The investigation shows that the Wettin landgraves of Thuringia primarily used it to expand and consolidate their own sovereignty. The study examines the importance of feudalism with regard to the expansion and consolidation of sovereignty by the Wettin landgraves of Thuringia between 1382 and 1440 pronounced noble self-image. Feudalism offered a suitable means of asserting their sovereignty and integrating the nobility into their own ruling association. The investigation draws a dedicated picture of the late medieval feudal system, which also offers a unique insight into the aristocratic landscape of the Landgraviate of Thuringia and its extended regions.