Princes in the Tower "the murther of his nephews towards the world", indicating that the boys did indeed meet their end during Richard's days. It is also unlikely that the princes would have been kept alive in secret by Richard for 2 years after their last sighting while rumours of his responsibility for their murder circulated. Some writers have also accused John Howard, 1st Duke of Norfolk; Margaret Beaufort, Henry VII's mother; and Jane Shore (Edward IV's mistress). Pollard writes of these theories: "None deserve serious consideration. The problem with all these accusations is that they beg the question of access to the Tower
Princes in the Tower of Scotland. After a failed attempt to invade England he was captured. He retracted his claims, was imprisoned and later executed. Many modern historians believe he was an imposter, whose supporters accepted his claim for political reasons. The fact that two persons claimed to be Richard led the 18th century writer Horace Walpole to argue that Richard had in fact escaped death, and that Warbeck genuinely was Richard, a view also supported by Malcolm Laing. Walpole, however, later retracted his views and stated that he now believed the princes to have been murdered by Richard III to secure his hold