St Teilo founded a monastery and was made Bishop at Llandeilo Fawr in Carmerthenshire. The well used for baptisms can still be seen below the church at Landeilo. He founded another at Penally near Tenby overlooking the sea. A fine 10C cross can be seen in the church. He also built a church at Llandaff; his tomb at Llandaff was opened in the 18C, and the corpse was wrapped in leather, still sound, and with his pastoral staff, pewter cross and chalice safely in place by his side. A relic consisting of a piece of his skull can be seen.
O Bishop and monk of early Wales
great was your church at Llanteilo Fawr
Famous for learning and the wise ways of the heart
many were the disciples who came to you;
pride of Llandaff pray for us still!