The medieval diocese of Glasgow was refounded around 1114–18 by the future King David I, then ruling southern Scotland as prince, who restored the ancient see of Kentigern and installed his tutor John as bishop. An inquest into the church’s ancient lands endowed it richly: the diocese eventually stretched across the whole south-west of Scotland, making its bishop one of the great magnates of the realm.
The see’s first great battle was for independence. The archbishops of York claimed authority over Glasgow, and behind them stood English kings with uses for such claims; Glasgow’s bishops fought the point at the papal court for decades until Rome declared the Scottish church — Glasgow prominent within it — the ‘special daughter’ of the papacy, subject to no archbishop but the Pope himself. It was as much a national victory as a clerical one.
The builder-bishop was Jocelin (1174–99), who did more than any single figure to make Glasgow: he rebuilt the fire-damaged cathedral and enshrined Mungo’s tomb, secured the burgh charter and the fair from William the Lion, and commissioned the Life of Kentigern that gave the city its founding legend in literary form. His thirteenth-century successors, above all William de Bondington, raised the glorious choir and lower church that survive; the fifteenth century added the stone spire and the chapter’s full pomp.
The bishops’ later gifts made the city’s future. In 1451 Bishop William Turnbull obtained the papal bull founding the University of Glasgow — taught at first in the cathedral precincts — and in 1492 Bishop Robert Blacader had the see raised to an archbishopric, capping a long rivalry with St Andrews and placing Glasgow at the head of its own province. Around the cathedral spread the physical church-city: the Bishop’s Castle, the canons’ manses, of which Provand’s Lordship alone survives, and the hospitals and friaries of a town that lived by its church.
It all ended in a generation. The Reformation of 1560 swept away the Catholic hierarchy; the last medieval archbishop, James Beaton, withdrew to France taking the cathedral’s treasures and archives with him. But the bishops’ legacy proved more durable than their office: the cathedral, the burgh, the fair, the university — medieval Glasgow’s four foundations, every one a bishop’s work, and every one still here.