A colleague of mine at Lancing, a very learned Presbyterian Classicist, was chrismated into Orthodoxy around this time of the year, and took the name Markos in honour of S Markos Eugenikos, the leading opponent of Unity at the Council of Florence (1438-1439). (My friend later tested his vocation on the Holy Mountain, where they made him repeat his Baptism!)
I was reminded of S Mark when Professor Tighe told me about a very positive article on Palamism by a Greek Catholic scholar Fr Christiaan Kappes (afkimel wordpress 27 June 2016) which contextualises S Mark. Perhaps he is rather an interesting Saint to think about on this his Feast Day, on the Second Day within the Chair of Unity Octave!
S Mark was not immediately canonised by the Byzantine Churches. Perhaps, in those decades, they had more pressing things to worry about! Finally, in 1734, Seraphim Patriarch of Constantinople did canonise him; I wonder if this action can possibly have had anything to do with the decision of the Patriarch of Antioch and his Synod, the previous decade, to enter into Full Communion with the (other) See of S Peter. Was Patriarch Seraphim making a point in his own contemporary church politics by canonising this figure from a controversial past? Some Latin Catholics might be able to think of modern examples of this very same phenomenon of Political Canonisation!
Wikipedia says that S Mark is on the Calendar of the Melkite Church. I haven't found him on the copy of that Calendar (1960s) which I possess, although many of the saints who were canonised by the separated Byzantine churches are there. Can anybody throw any light upon this?