Hello, I had say Manuel I, but not sure at all.
I didn't find an exact match in the DO : the legend doesn't seem to fit well. However it shares some similarities with that one https://en.numista.com/catalogue/pieces70299.html
First picture : Emperor crowned by the Virgin Mary.
Second picture : Seated Christ.
Hello Thomas
Have a look at this site;- https://www.forumancientcoins.com/board/index.php?topic=117611.0
Seems very similar to a fake of a gold Hyperperon of John III Vatatzes.
On the reverse you can see (I)omega which is the sign for Ioannis followed by DE the beginning of Despote (master or Lord) as Cycnos says.
It seems as if it might be a fake but, you need more of an expert than I am.
James