Who is Erland from The Wolf and the Dove and what is their importance?

Erland is Aislinn's father. When Ragnor arrives with his men, a herald begins reading a list of demands and Ragnor gives Erland, then sixty-five years old, no chance to negotiation. Enraged, Erland strikes the herald, beheading him, and Ragnor soon kills Erland. As things settle into routine, Wulfgar stands at Erland's grave and pledges to care for Darkenwald and its people, and that Erland will have many grandsons playing on the property.