Mauchline Parish Church was a Covenanters' stronghold. The minister during these troubled times was the Reverend George Young, who signed the National Covenant in Greyfriars' Churchyard in Edinburgh in 1638 and subscribed to the Solemn League and Covenant in 1643.
The Covenanters' Flag above was first used in an engagement between Covenanters and Royalist troops on Mauchline Muir and was later carried at the Battles of Drumclog and Bothwell Brig in 1679.
The flag was handed over to the Kirk Session for safekeeping in 1955 and thereafter gifted to the congregation in 1980. The Covenanters' Flag is now framed and displayed on the south wall of the church.