Castle Semple Collegiate Church was founded by John, Lord Sempill in 1504. He was killed at the Battle of Flodden in 1513 and the church was duly extended with a three-sided apse to accommodate his ornate tomb. The effigy does not survive.
Collegiate churches were built to house a college of clergy. Their duties were to pray for the souls of the Lord and his family, such was the importance placed on ensuring the speedy passage of souls through purgatory and into heaven during the medieval period.