Selection of references used:
- 1: John J. Robinson, Born in Blood, ISBN:0-87131-602-1, M. Evans & Company / New York, Geoff Bath
- 2: T.F. Tout, The History of England
- 3: John Gillingham, The Life and Times of Richard I, 1974, George Weidenfeld and Nicholson Limited (1974)
- 4: Caroline Bingham, The Life and Times of Edward II
- 5: G.A.Cambell, The Knights Templar. Their rise and fall