Nicknamed "Mavropous" (Blackfeet), he was a man of great scholarship and true spirituality. When the Emperor Alexius Comnenis was very old, John became Metropolitan of Euchaita. He is particularly famed because St Basil, St Gregory the Theologian and St John Chrysostom all appeared to him (see January 30th), and revealed to him how they are, all three, equally glorified in heaven. After this vision, the bickering among the people was quieted, for they had been quarrelling about which of the three was the greatest. St John also composed the well-known Canon to the Most Sweet Jesus and the Canon to the Guardian Angel, and he also compiled several instructive books. He entered peacefully into rest in the second half of the 11th century.