When was Saint John the Evangelist canonized?

A:

The term 'evangelist' is often used for the authors of the New Testament gospels, so St John the Evangelist was the author of the fourth gospel. Ever since the second-century Church Fathers attributed the fourth gospel, which was written anonymously, to the apostle John, it has generally been assumed that St John the Evangelist is indeed the apostle John. It comes as a surprise to many to learn that we do not really know who the author was or even if he was called John. Modern New Testament scholars say that the gospel could not have been written by an eyewitness to the events portrayed, so this should mean that the Evangelist was not the apostle John. In either case, we do not know just when or where the apostle John or the Evangelist died.

There is a tradition that the apostle John died around 100 CE in Ephesus, but this is unreliable and arose because he was thought to have been the author of the fourth gospel and of Revelation. Another, probably earlier tradition is that the apostle John was killed by Jews, perhaps in the Holy Land, but this tradition is just as unreliable as the first.