Who was Gwynno? According to one local tradition, he was one of the disciples of the great Illtud, who founded the monastery at Llanilltud Fawr (Llantwit Major). The church at Llantwit Fardre, south of Pontypridd, is dedicated to Illtud, and the old church at Ystradyfodwg, in the Rhondda Fawr, is dedicated to another of his followers, Tyfodwg. They are the ‘three saints’ of Llantrisant, the old hilltop town west of Pontypridd. John Morgans, the minister who founded Llanfair church in Penrhys, liked to picture the old abbot and his young followers meeting at Penrhys, the holy place between their three churches.
A gravestone at St Gwynno's church marks the last resting place of the legendary Welsh runner, Guto Nyth Bran, born Griffith Morgan. He lived at Nyth Bran farm, hence his nickname ‘Guto Nyth Bran’. He was so fast that he could outrun a hare and catch birds in flight. In races he beat all comers until he ran out of opposition but came out of retirement at the ripe old age of 37 to race against a new runner called Prince. Triumphant, as ever, unfortunately a congratulatory slap on the back from Sian-O-Shop, his trainer and sweetheart, caused Guto to collapse and die. He completed the 12 mile course in 53 minutes, the current world best time for 3 miles is about 12 minutes 12 seconds and that's on a level track! His achievements inspired the annual Nos Galan races around Mountain Ash.