Who is Denys Finch Hatton from Isak Dinesen: The Life of a Storyteller and what is their importance?

Denys Finch Hatton was Isak Dinesen's lover while she was in Africa. Their romance was intense but not in the usual way. Denys was a confirmed bachelor with absolutely no interest in marriage. He even balked at fully committing his life to Dinesen and often fought with her about this. He would stay for a while, be gone for a while, and repeat this pattern throughout.