I have been informed by a viewer: The inscription above the first one on the left says "Sowrb T'eodoros", St. Theodore. According to his "Vita", he was a Christian military commander from Amasia, and was burned alive in the year 306, during the emperor Diocletian after having arsoned the temple of Rhea. He was also known as "dragon-killer". And: the third one is St. George, also a dragon-slayer.

From the middle one I can only read a couple letters, likely St. and an "S". The third dragon-slayer is usually St. Sarkis or Sargis.