Pisanello made several sketches of John VIII Palaiologos during his visit at the council of Florence in 1438, for a medal he was commissioned to make for him (possibly by Leonello d'Este), on one of his sketches:Huck wrote: John VIII Palaiologos, since 1425 the "Eastern Emperor", which in 1439 appeared during the council in Florence, travelled in 1423–24 to Venice, Milan and Hungary (? also to Florence ?) to ask for aid against the Osmans in person.
we see the following Arabic inscription:
which translated reads:
"Glory to our sovereign lord al-Malik al-Mu'ayyad Abu Nasr Shaykh" (translated by Mohamad Ballan, University of Chicago) ,
another translation reads:
"Concerning the Master, the Sultan, the King, El Moaid-Abu-El-Nasr, God grant [Glory] his Victory."'' The Arabic is said to be slightly incorrect,but the reference to the Mameluke Sultan El Moaid- Abu-El Nasr) is plain. He reigned from 1412 to 1421.'
Some preparatory drawings for Pisanello's Medallion of John VIII Palaeologus by Michael Vickers
Apparently the Arabic text was copied from an inscription of gold on blue on a garment that was gifted to the Emperor (beloved of the Pope of Rome) by Mamluk SultanAshraf Sayf-al-din Barsbe (also known as Abu-El Nasr,)who reigned from 1422 to 1438.
Mameluke Sultan El Moaid- Abu-El Nas (1412 to 1421) we have previously met in our discussion on the Mameluk kanjifa cards - having been recorded to have gambled playing at kanjifa, probably in Syria (Damascus or Allepo) around 1400:
Kanjifa of course was the name of the Mamluk playing cards. Here is the word Kanjifa at the top right hand corner of the Mamluk King of Swords: