Charles had merely to recognise Monmouth as his heir to free himself from every trouble and assure the future of his country. Nothing would induce the King to betray the succession. Sensualist, libertine, agnostic, dilettante, he had one loyalty – the royal blood, the legitimate succession. However painful it might be for himself and his realm, he conceived it his sacred duty to pass the crown to a brother whose virtues and whose vices alike rendered him of all others the man, as he knew well, least fitted to wear it.

Winston Churchill, A History of the English-Sp…, loc. 1219