 In the late Northumbrian period, St Cuthbert's may have served as the minster for an area stretching from the environs of Edinburgh to the River Almond in the west and the Pentland Hills in the south.The parish had been reduced in size in the mid-13th century by the detachment of Liberton and Corstorphine.Prior to the foundation of St Giles' in the 12th century, the parish may also have covered the burgh of Edinburgh itself.