This classic 1 Stotinki stamp of Tsarstvo Balgariya features a detailed architectural design later overprinted “TRACIA” in red, issued during Bulgarian administration of Thrace in the early 20th century. Such overprints were applied to existing Bulgarian definitives for provisional postal use in newly occupied territories. The bold red overprint represents an important geopolitical transition period following the Balkan conflicts. Collectors value these issues for their historical significance, postal usage rarity, and regional occupation status. Well-centered examples with clear overprints are especially desirable in Balkan philately collections.