Christian saint and theologian
Joannicius the Great or Ioannikios was a Byzantine Christian saint, sage, theologian and prophet. Well known for his devoted asceticism and defense of icon veneration, Joannicius spent the majority of his life as a hermit on Mysian Olympus, near what is today Bursa, Turkey. Joannicius lived during the reign of Emperor Theophilos, a noted iconoclast, which contrasted with Joannicius's embrace of icon veneration. Icon veneration was later restored to the Byzantine Empire under the reign of Empress Theodora, a move that some devotees ascribe to Joannicius's influence and prophecies. Joannicius served in the Byzantine army in his early years before devoting his life to ascetic study and monastic contemplation. He is venerated with a feast day on November 4 in the Eastern Orthodox Church and Catholic Church.