The French accept Perkin Warbeck as the rightful claimant to the
English throne. Although most probably Flemish in origin, Warbeck
claimed to be Richard of Shrewsbury, 1st Duke of York, the younger
son of Edward IV, who was imprisoned in the Tower along with his
brother Edward V under the kingship of Richard III.
Citation:
Editors. "French accept Perkin Warbeck as rightful claimant to the English throne".
The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=13900, accessed 22 May 2013.]