Death be not proud - C. F. Dunn

Following the vicious attack by a psychotic colleague, and reeling from the discovery that Matthew Lynes is not all that he seems, Professor Emma D'Eresby flees the university college in Maine to her home town in England. Broken physically and emotionally, Emma drifts until, fearing for their daughter's sanity, her parents invite a family friend to assess her. In the course of their conversation, Emma discovers that he spoke to Matthew over thirty years before, and she concludes that Matthew must be hiding a profound secret. Spurred into action, she traces Matthew's family name back, making a startling discovery - that Matthew was betrayed during the English Civil War where a clash with his uncle left him fighting for his life. But instead of dying he not only lived, but persisted, growing steadily in strength and surviving events that would have killed any other man. But Matthew also has the memories, and baggage, that come with his longevity :