For over 500 years, the mysterious disappearance of two English princes has perplexed the world. Historians have long assumed that Edward V and Richard, Duke of York were murdered in 1483 by their uncle, Richard III. But Dan's guest today brings a dramatic new theory to the table.

Philippa Langley played a crucial role in the discovery and exhumation of Richard's body in 2012. She has since turned her attention to the greatest mystery that surrounds his life; did he really kill his own nephews to seize the English throne? After delving into one of history's greatest cold cases, Philippa believes she has finally solved this royal mystery...