The role of the hippocampus in memory has been known for many years. With the discovery of place cells, it became clear that the hippocampus has a special role in spatial memory and navigation. Although the hippocampus is critical in episodic memory, rodent studies have focused on spatial cognition and human studies on remembering items in a list. Recent studies have suggested that the hippocampus may be important in the relationship between episodic memory and temporal organization, and research has begun to shift in this direction. The view that the hippocampus is basically a spatial mapping and navigation center has been replaced by the view that it supports memory by organizing memories in a spatial and temporal context. In this section, the role of the hippocampus in memory is emphasized in relation to time.