StGregoryIlluminator.TheotokosPammakaristosChurch.Istanbul.Mosaic.800 Published March 23, 2012 at 800 × 600 in Morning Prayer 3.23.12: Gregory the Illuminator, Bishop & Missionary of Armenia, c. 332 Next → Gregory succeeded in converting King Tiridates of Armenia to the Christian faith, and together they persuaded the people to join them, making Armenia the first Christian nation on earth. (Theotokos Pammakaristos Church, Istanbul)