The hippocampus and related medial temporal lobe (MTL) structures are known to be important for declarative memory. Yet, their precise role remains unclear. In three studies, we sought to characterize the role of the hippocampus in encoding, remembering, and imagining. The first study assessed the role of the hippocampus in encoding and remembering memories for words encountered in a laboratory setting. The second study assessed the role of the hippocampus in encoding and remembering real- world events. The third study assessed the role of the hippocampus in remembering natural autobiographical memories and imagining future episodes. We conclude that the hippocampus plays a broad role in declarative memory, functioning to encode information whenever the capacity of working memory is surpassed.