This article is an introduction to the thematic issue of Forum Historiae 1/2017 on environmental history in the territory of Slovakia and East Central Europe in the period between the 18th and 20th centuries. Apart from introducing the studies published in the issue, informing on the environmental historical research in Slovakia, the authors propose a theoretical scheme for historical research of environment. They introduce a set of working definitions centering on the conceptual triad: nature, landscape, and environment. The definitions proposed are departing from the milieu of geography and environmentalism setting them scale-wise into a hierarchy – the scheme positions the concept of environment as the widest, incorporating all properties and factors that a living subject can encounter. It is followed by a narrower concept of landscape, that is, living space defined by the natural as well as men made features of the living area; and lastly the concept of nature is the narrowest, meaning those parts of the planet where there are no apparent traces of human activity. As the authors are aware of certain limits of their ideal-typical definitions, they hope to encourage further discussion on this matter.