Turn right beneath the lamps towards the nave.
Above the door on the left is a plaque memorialising a dramatic event relating to Clerkenwell’s history of radicalism. Middlesex House of Detention or Clerkenwell Prison used to stand where stands the present Old Sessions House, opposite the church to the right as you look down the hill.
On the night of the thirteenth of December 1867 a plot was hatched to free a member of the Irish republican brotherhood who was being held on remand in the prison by destroying the wall with gunpowder. However a full barrel of gunpowder was used which had the terrible effect immediately of destroying residences in the area and killing fifteen people and disabling forty more. The plaque gives more details about the event and the consequences for those who lost their homes.