This is a story of conspiracy and betrayal, of a lust for power and a lost allegiance; the story of the man who killed King Richard III. In this documentary we set out to prove that the Welshman Sir Rhys ap Thomas, master of Carew Castle in Pembrokeshire, killed King Richard III, changing the course of British history. We uncover what drove him Rhys ap Thomas to betray not only his master but a King – and we reveal his remarkable story; from a childhood embroiled in the War of the Roses and exile to the continent, to a determined...