Historians have disagreed on this point virtually since June 1483 when the boys disappeared from view inside the Tower of London. Most blame Richard for their deaths. Some put the blame on Henry VII. A retired policeman writing under the name Mark Garber wrote "Cold Case re-opened" in which he tries - and largely succeeds - in working purely with the "evidence". However, there are questions that need answering. Can we do that from a distance of 530 years?
Is there any evidence that anyone killed the boys?
Are the bones discovered in Charles II's reign and laid to rest in Westminster Abbey theirs or not?
Were the forensic capabilities in 1933 when these bones were last examined, enough to be convincing?
Richard III declared his brother's marriage invalid via the Titulus Regius - and therefore the children of that marriage illegitimate because of a pre-contract. However the lady concerned died in 1468 and the future Edward V was not born until 1470, so even if Richard was correct, surely the boys were legitimate?
If the Titulus Regius made the children legally illegitimate, why would Richard need to kill them?
Mark Garber assumes that Elizabeth of York was sleeping with Richard during the summer of 1484 whilst Richard's wife Anne lay dying. Seeing that her mother succeeded in repulsing Edward IV's advances until he married her and her eldest daughter would know this, I have little doubt that this information is wrong.
Henry VII rescinded the Titulus Regius, thus making all the children, including his soon-to-be wife, legitimate. If he could do this, it meant the princes were once more legitimate and had a prior claim to the throne. So, does it mean he knew the princes were dead and if so, how?
Against that last point, when Perkin Warbeck was running around declaring himself to be the lost Duke of York, Henry was known to be "nervous", which would indicate he thought Warbeck might be who he claimed to be.
The characters of Richard and Henry are important. Richard is known to have been charming and family oriented, yet he could be utterly ruthless - see the death of Hastings, accused, condemned and executed in the space of an hour. Henry is supposed to have been cold, calculating and paranoid. Yet he kept the Earl of Warwick alive until 1499. Do we believe that Elizabeth of York would have married him had she known that he killed her much-loved brothers?
It seems that for every point, we can find a counterpoint. However, I have seen a prospective culprit, if the boys were indeed murdered, who is neither Richard nor Henry. And I am having such fun trying to work the theory and see if it holds water. Watch this space.