St Barnabas Church is very special, in a number of ways. It is believed to be one of only 6 churches built during the time when Oliver Cromwell was Lord Protector of England, (1653-1658) between the reigns of King Charles I and Charles II.

There was a previous medieval church on the site, probably built in the 13th century. It was completely destroyed during the siege of Brampton Bryan in 1643–44. After the Restoration of King Charles II, Sir Robert Harley arranged for a new church to be built on the same site. In keeping with his Puritan views, he wanted a plain, box shaped church without many of the traditional medieval elements.

Recent studies of the growth rings in the roof timbers have shown that many of the trees used were freshly felled in 1644, the year after the siege, disproving the long-held belief that some of the timbers were recycled from the castle ruined in the fighting.