Byzantine Seal of Martialios the Metropolitan? 6th/7th Century?

[pogh_poor]

I purchased a second and even more handsome Byzantine seal with the Virgin Mary the infant Jesus on her lap with crosses on each side within a pellet dot border. On the reverse is a monogram.  It appears to be 6th/7th Century.  It is large and measures approximately 22.32 mm by 21.15 mm.  It weighs 10.59 g.  The seller deciphered the reverse monogram as reading as ΜΑΡΤΙΑΛΙΟΥ ΜΗΤΡΟΠΟΛΙΤΟΥ - of Martialios Metropolitan.  I could find no reference to a  Martialios.  Does it seem to be a proper interpretation?   All ideas would be appreciated.  Pogh_poor

[Gert]

The problem with these complex monograms is that many times multiple solutions are possible. So if we would accept 'ΜΗΤΡΟΠΟΛΙΤΟV' then the letter A remains for the personal name. So all names containing A and any letter of 'metropolitou' would be possible. Either Paulos (ΠAVΛOV) or Elias (HΛIA) would be much more probable than Martialos, an originally Latin name that must be very rare if at all attested for the Byzantine world.
Regards
Gert