But to murder children? Then, as now this is special category of horror.
The 'Princes in the Tower' were actually King Edward V of England and his brother, the 1st Duke of York. Despite the grandeur of their titles, the two boys just 13 and 10 respectively when they were sent to the Tower of London, ostensibly for their own safety by Richard, Duke of Gloucester. Shortly afterwards, Richard declared himself king Richard III and the two boys were never seen again - although the date on which they were last seen remains vague.
It is presumed that they were murdered on Richard's orders. He had seized the throne by having Parliament declare their line to be illegitimate. In the "Titulas Regius" act it was asserted that the boys had been born illegitimately as the marriage between their father (Edward IV) and mother had been found to be invalid.
Naturally, the continuing existence of the boys themselves represented a threat to Richard's own claim. History had shown time and again that living claimants to the throne could easily raise sympathies and even armies to threaten a monarch.
Most suspect that the boys - last seen playing in the grounds of the Tower of London in the summer of 1483 - were thus murdered in cold blood to ensure that Richard's claim to the throne could not be challenged.
In 1674 bones of two skeletons were recovered from the foundations of a staircase within the Tower of London. They were said to be those of children and thus as proof of the Princes' murder - confirming in the public mind the already popular belief that Richard III had had the two smothered by James Tyrell. In 1678, the bones were interred in an urn at Westminster Abbey.
In 1933, the bones were disinterred for scientific study. As this preceded by several decades the advent of DNA testing and modern analysis techniques such as carbon dating, the results can tell us little. It was established that the bones were of young children of approximately the right age for the Princes, but the date of their death could not be told, nor their sex. Until the bones are disinterred for modern forensic analysis, their identity and relation to the princes must remain speculative.
Of course, not everyone believes that the princes were actually murdered. Many hold that Richard actually had them spirited away and hidden. The mystery of their disappearance allowed the claim of Perkin Warbeck to be believed by some of those who wanted to see an end to the Tudors.