Saint Dimitrios of Thessaloniki was a Christian martyr and military saint who lived during the late 3rd and early 4th centuries. Born in Thessaloniki, he served as a high-ranking officer in the Roman army under Emperor Maximian. Despite his position, Dimitrios was a devout Christian and openly preached the faith, which was forbidden at the time. When the emperor discovered his beliefs, Dimitrios was imprisoned and eventually executed around 306 AD. He is especially venerated in the Eastern Orthodox Church as a protector of Thessaloniki, credited with miraculous interventions during times of war and plague. His feast day is celebrated on October 26th.