Sentence:  The little island of Iona became the refuge of the sons and some <WSD>thanes</WSD> of Athelfrith, banished by Edwin. 
Meaning of the word marked with <WSD> tags:  A rank of nobility in pre-Norman England, roughly equivalent to baron.<ref>"[http://books.google.com.au/books?id=6ZsRAAAAIAAJ&pg=PA594&dq=%22There+were+two+orders,+the+king%27s+thanes%22&hl=en&sa=X&ei=26ygUYzWFOyXiAfssoHACw&redir_esc=y#v=onepage&q=%22There%20were%20two%20orders%2C%20the%20king's%20thanes%22&f=false thane]", entry in '''1852''', "Putnam's Home Cyclopedia: Hand-Book of Literature and the Fine Arts", p594 — The '''thanes''' in England were formerly persons of some dignity; there were two orders, the king's '''thanes''', who attended the kings in their courts and held lands immediately of them, and the ordinary '''thanes''', who were lords of manors and who had particular jurisdiction within their limits.(...)After the [Norman] Conquest, this title was disused, and "baron" took its place.</ref>