Dunstan, a royal prince of Wessex, became Archbishop of Canterbury in 960. As well as being an outstanding pastor and royal advisor, he was a scholar, teacher, metalworker and artist. This is believed to be his self-portrait, bowing in adoration of Christ.
This post from the British Library by Andrew Dunning includes a number of portraits of Dunstan from mediaeval manuscripts, as well as a prayer written in his own hand, as seen above the kneeling figure in the picture above.
Saint Dunstan’s church, Canterbury, outside the city walls to the north of town.