The Levellers were a group of radical thinkers, whose views challenged Parliament's control during the English Civil War. They wanted equality for all, a level society and are considered by some to be the first socialists.

In 1649, a group of soldiers, angered by arrears in pay and with little hope of being paid the money they were owed, mutinied at Salisbury and began to march to join other Levellers near Banbury.

Government troops caught up with and surrounded the mutineers near Burford and some 340 prisoners were locked in the church. During their imprisonment, they left evidence of their time there, in particular a carving by Anthony Sedley in the lead on the font, which is dated 1649. There is also a "nine men's morris" board carved into one of the tombs in the Bartholomew Aisle.

On May 16th, 1649, the ringleaders were taken from the church and shot. The other prisoners were taken onto the roof of the Lady Chapel to watch, but we have no evidence as to where the executions took place or where the bodies were subsequently buried.  The other prisoners were pardoned, but the cause of the Levellers petered out after this defeat.

Today a plaque on the church wall commemorates the executed soldiers and Levellers Day is held in the town each year to commemorate the event.