During the creation of some digital works of historical content we take under consideration the modern concepts about theory of knowledge, which make an introduction into the field of the Humanities, and especially history, the concept of the entity, as an autonomous cognitive element. Each entity has a name, description, characteristics and qualities and combined with other entities composes hierarchical, relational, or/and dependential systems. In other cases, as entities we consider mainly wider thematic units of geographical, temporal or/and cultural character, suitable to record and include data, events and phenomena, their causal relationships and the (usually) deviant interpretations. It is however necessary to distinguish the historical ontological approaches from the linguistically originated ontological models of semantic organization, which support theoretically the development of object oriented databases or knowledge bases (OODB-OOKB). Possible in the future the continuous elaboration of an ontology of history will achieve its complete expression in a respectively complete ontological model of semantic organization of historical information