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 Jan Allertz (Recorder of Rotterdam), all state that Richard killed the princes before he seized the throne (thus before June 1483). De Commines' "Memoirs" (c.1500), however, identifies the Duke of Buckingham as the person "who put them to death". Only Mancini's account is truly contemporary, having been written in London before November 1483. The Croyland Chronicle and de Commines' account were written three and seventeen years later, respectively (and thus after Richard III's death and the accession of Henry VII). Markham, writing long before Mancini's account was discovered, argued that some accounts, including the Croyland Chronicle, might have been authored