http://en.wikipedia.org/wiki/Richard_III_of_England
Richard had a reputation for leading a killing charge that ended most of the battles he fought with him winning by the force of that cavalry charge. Richard was doing such a charge when he was killed. The above cite by soldiers who had defected earlier to Henry's VII's side, but I have read sources he was stabbed in the back by one of his own men as the charge was about to succeed.
The general view as to that battle, was Richard was on his way to winning the battle when he died. The Battle ended with his death.
As to the killing of his nephews, that is open to debate. The main reason is that the princes died in SECRET. If you are ruling a Kingdom, and someone else has a claim to that throne. you eliminate that threat. Richard III had found out that his older brother, Edward IV, the father of the princes, had promised to marry a woman and then had sex with her BEFORE he married the princes mother. That act was enough to make that earlier woman the true wife of Edward IV, and that made Edward subsequent marriage to the princes mother void and both children illegitimate. This was the justification for Richard III taking the throne as King instead of Regent. Now, that may have been the law, but it was not uncommon at that time to ignore the law when it was politically convenient, thus just because the princes were illegitimate did not mean they could not make a claim for the throne (i.e. the Common Law Marriage never took place, and they were legitimate children of Edward VI and thus the rightful kings of England). Thus the princes were still claimants for the throne. Richard III and Henry VII would have killed them for that reason alone.
On the other hand, you do NOT want a pretender appearing to be that threat, thus the death must be clear, not covered up. Given that we are talking about young pre-teens, simple murder would NOT suffice, the people will grow to hate you. Thus both Richard III and Henry VII had good reasons to kill the princes, they also had good reasons to make sure the death did NOT end up turning people against them. A natural death, that could be confirmed by doctors, followed by a State Funeral, where everyone can see the bodies is ideal. Thus you make sure everyone can see what the prince died of and kill any conspiracy theories. A story of illness, leading to a rapid death could be arranged, followed by a State Funeral so everyone cans see that the princes died a nature death. IF Richard III or Henry VII was involved in the deaths of the princes I would have expected something like that. The princes were threats, not by themselves, but could be used by others to justify a revolt. Thus most historians who have looked into the situation have a problem with EITHER RICHARD III or HENRY VII killing the princes.
The chief suspect is believed to be Lord Buckingham. The theory goes during his rebellion of 1483, Buckingham had the princes killed so he could later tell Henry VII he had done so and be rewarded for it. The problem was Buckingham fell into the hands of Richard III, who properly executed Buckingham for his revolt. Richard III, seems to have accepted that the Princes were dead in the last two years of his rule, they did NOT come up as he look to designate a heir (Which indicated they were dead). Henry VII seems to have looked for the princes after at least one revolt against Henry VII by a pretender saying he was one of the princes, indicating Henry VII did NOT know of they were dead. The princes were ALIVE before Buckingham's rebellion in 1483 AND would have fallen into the hands of Buckingham during his revolt against Richard III. Thus he had the opportunity. He had reasons to kill the princes (To appease Henry Tudor later Henry VII). Henry VII's later attempt to blame Richard is consistent with Henry VII NOT really knowing what happened to the Princes. Richard's various effort to designate an heir after the death of his wife and son seems to indicate he knew the princes were dead. Richard's refusal to tell the people the princes were dead implies he did NOT have a plan on how to handle their deaths (Thus supports a killing by a third party). Both Richard III and Henry VII would have paraded the princes if they were alive, AND if they had died would have paraded the body and blame the other for causing their deaths.
Thus it looks like both Henry VII and Richard III are innocent of the crime, but the Duke of Buckingham is a top contender for the claim. The Duke had been close to Richard III before his revolt and then tried to get support from Henry VII during the revolt. Thus the Duke can be viewed as having worked for both men (And mostly for himself). Killing the princes would be an easy way to show either claimant that he still had the princes, even if he was defeated, for no one could produce them. The THREAT that the Duke of Buckingham still had the Princes is all the Duke needed, the actual living princes unimportant. Thus the Duke killed the Princes, but then the Duke was not only defeated by Richard III, he was CAPTURED by Richard III. As long as the Duke was free, the threat that the Duke had the princes was all the Duke needed, but once captured Richard III could DEMAND that the Duke return the princes, and when the Duke couldn't, it was clear the Duke had killed the Princes and without any other reason to keep his alive Richard III had the Duke of Buckingham executed. This explains Richard III's subsequent action NOT to name the princes as his heirs (For Richard III knew they were dead) AND Henry VII's subsequent actions when he looked for the Princes.
For more on Buckingham's rebellion of 1483:
http://en.wikipedia.org/wiki/Buckingham%27s_rebellion#Buckingham.27s_revolt
I am sorry, the death of the Princes done by the Duke of Buckingham is the best explanation of what happened to the Princes. Henry VII's claim to the throne was weak, and Richard III being dead, blaming Richard III was the best way Henry VII could address why he was King instead of the Princes.
= new reply since forum marked as read
Thanks for the laugh!
