Republicans who had ruled the Netherlands for years, the De Witt brothers were good friends with the philosopher Baruch Spinoza. Johan De Witt was a world class mathematician who opposed the House of Orange. All of his dreams of a rational society fell apart when his mathematics could not stop the muskets and cannon of the French and English when they invaded the Netherlands in the year 1672, the Rampjaar or Disaster Year. The brothers were assassinated by a mob, their bodies hung and torn apart. It was their death that had a profound impact on Spinoza. There is a story often repeated that Spinoza would visit the site where the two brothers were hung, gutted and their inner organs eaten by the mob in a cannibalistic frenzy every year and leave a piece of paper with words Ultimi Barbarorum, ultimate barbarianism.