I read HANH on the first line, which does not make sense in Greek as far as I can think of. I think it must be a form of
Johannes in the dative - I(o)an(n)è. Either the omission of omega is an
orthographic error, or the seal's owner was not a Greek, and greacized
his name. There are many examples of
seals mentioning non-Greek language names, including Latin western names.
In many languages, the name
Johannes can lose the o in its
pronunciation (including in my own native language Dutch: Jan. Same happens in English,
Ian and
German, Hans). If a person named Jan would be commissioning a seal, he could be wanting to graecize
his name, including the dative case, which yields IANH.
He was a [ch]artou[l]a[rios].
Here's a seal from my personal
collection that shows a similar process. It belongs to a person named IOBANE who is a vestes. IOBAN is the greacized form of the Georgian name Iovan (also a form of
Johannes).
Regards
Gert