Question: What island is part of the Islands of Furness and has a castle that was used as a base by the Yorkist pretender Lambert Simnel in 1487?
Sentence (from "Piel Castle"): It was used as a base by the Yorkist pretender Lambert Simnel in 1487, but by 1534 it had fallen into ruin and passed into the hands of the Crown.
Relevant evidence: Yes