Saint John Damascene spent all of his life under Muslim rule. In addition to being a poet and a theologian, John was a defender of the use of holy images in the liturgy.
In the summer of 726 a volcano erupted in the Aegean Sea causing Tsunamis and a significant loss of life. The Byzantine emperor Leo III saw this, along with recent military defeats at he hands of Muslim forces, as a sign of God’s displeasure. Leo felt this displeasure was due to idolatry, the worship of images, and ordered an image of Christ that was over the palace gate to be taken down. Supporters of the image feared that its removal was an act act of sacrilege and murdered the men sent to carry out the emperor’s orders. This began a struggle between those opposed to images, iconoclasts, and those in favor of them, iconodules, that resulted in the emperor banning the use and production of holy images in A.D. 730.
Saint John wrote against the iconoclasts, in favor of sacred images. Since he lived in Muslim territory his enemies were powerless in their efforts to silence him.
Saint John is the patron of pharmacists, painters of sacred images, and theology students.