Kentigern (Welsh: Cyndeyrn Garthwys; Latin: Kentigernus), known as Mungo, was an apostle of the Scottish Kingdom of Strathclyde in the late 6th century, and the founder and patron saint of the city of Glasgow.
Kentigern was born at Culross in Fife. He was brought up by Saint Serf at his monastery there. Much of his early life is more legend than fact but it is said that he was the son of a pagan king of Gododdin in Lothian. His mother was cast adrift on a coracle in the Firth of Forth which was washed ashore in Culross in Fife where she gave birth to a son.
Looked after by St Serf in a nearby monastery, he was named Kentigern but his nickname St Mungo ("dear friend") is used more frequently. He became a missionary on the Clyde under the patronage of the Christian King of Strathclyde, Rydderach Hael, who procured his consecration as bishop. For some thirteen years he lived an austere life in a cell on the banks of the Molendinar Burn, making many converts by his holy example and his preaching. A community was established there and it grew to become the town and then the city of Glasgow.
As a missionary, he was building on the early Christian church left by the Romans. In 543 he became bishop of Cumbria which at that time straddled what has become the border of Scotland and England. He is reputed to have been a widely travelled bishop in the 6th century and to have founded many churches, including Stobo.
Kentigern spent several years in Wales and is said to have met St David, the patron saint of Wales. He returned to Scotland and is reported to have met St Columba.
One tradition tells that St Mungo baptised Merlin Sylvestris on a large boulder known as the “altar stone” a few miles to the east of Stobo Kirk. This is Merlin the pagan, nature-loving bard who lived in exile in the woods of Upper Tweeddale and who was one of the two pseudo-historical figures that were later merged to become Merlin of Arthurian legend. This stained-glass window can be viewed in the Stobo Kirk.