The notion of territory plays a major role in human and social sciences. Representation of this spatio-temporal object and computation of the changes occurring have been tackled in various ways. However, in an historical context, most approaches are irrelevant as they rely on geometric data, which is not available. In order to represent historical territories,we conceived the HHT ontology (Hierarchical Historical Territory) to represent hierarchical historical territorial divisions, without having to know their geometry. This approach relies on a notion of building blocks to replace polygonal geometry. This representation is further used to provide an algorithm to detect and characterize territorial changes in a knowledge graph. Said algorithm creates a knowledge graph of changes at multiple levels encompassing basic changes occurring in a single territory, and composite changes, which are the abstraction of several smaller changes into a large change. The approach was followed to produce 3 knowledge graphs available online. Each of these graphs allowed to set up an analysis of the evolution of the territories during the historical period they cover.