A saint carrying a spear and a quill pen. After some googling - St Maurice maybe? He fits with the metalwork, since he came from Egypt.
It is an Ottoman inspired Greek, possibly other Eastern Orthodox Christian, amulet/prayer case. The triangular shape is very Turkish/Ottoman. It would have contained a piece of paper with a protective prayer or blessing, and maybe other small protective items as well. I think your case dates from the early 20th century, and it could have been made for Orthodox Christians in Western Turkey. For centuries, Greece was occupied by the Ottomans, until 1821. There have also been Hellenic peoples in Turkey since antiquity. Although there are still Turkish Greeks/Hellenic Turks, as well as other Orthodox Christian Turks, in the Istanbul region of Turkey, most of them left Turkey for Greece in a 'population exchange' of 1923. Some of the Ottoman influence can still be seen in Greek folk silver, but because of the distinct triangular shape, it could have been made by Turkish Greeks or for the Turkish Christian market. The links of the chain also look more Western Asian than European.
