On this date, 16 February 1265, Simon had to move to avert a crisis over a tournament proposed between his sons Henry, Simon and Guy and the Clare brothers, Gilbert and Thomas, to be held at Dunstable on the grounds seen below as they look today. Parliament was in session at the time, and such a mock battle between these rival groups could easily spill over into nearby London. So furious was Simon with his sons that he warned them he would lock them away in a place where they would have the benefit of neither sun nor moon if they tried a stunt like that again. Gilbert was even more furious because of all the money he had spent organizing the tournament and lashed out at Simon for presuming to run the realm with the highhandedness of a “foreigner”. He left to sulk in Gloucester and begin collusion with Simon’s enemies to bring about his fall.