The Holy Great Martyr Demetrius of Thessalonica was the son of a Roman proconsul in Thessalonica. His parents were secret Christians.
Demetrius had already reached adulthood when his father died. Emperor Galerius Maximilian, who ascended the throne in 305, summoned the young man to his place and, convinced of his education and military-administrative abilities, appointed him to replace his father as proconsul of the Thessalonian region. The main task entrusted to the young proconsul was to defend the city from barbarians and exterminate Christianity.
Having accepted the appointment, Demetrius, instead of carrying out persecutions and executions of Christians, began to openly teach the city residents the Christian faith and eradicate pagan customs and the worship of idols.
When Maximilian learned that his newly appointed proconsul — was a Christian, and converted many Roman subjects to Christianity, the emperor's anger knew no bounds. Returning from a campaign in the Black Sea region, he decided to lead an army through Thessalonica to deal with the Solunsky Christians.
Having learned about this, Demetrius ordered his estate to be distributed to the poor in advance, and he himself surrendered to fasting and prayer, preparing himself to receive the martyr’s crown. The emperor entered the city, and Demetrius boldly confessed himself to him as a Christian and exposed the untruth and vanity of Roman polytheism. Maximilian ordered the confessor to be imprisoned.
At dawn on October 26 (November 8, new style), 306, soldiers appeared in the underground dungeon of the holy prisoner and pierced him with spears. The body of the holy great martyr Demetrius was thrown out to be eaten by wild animals, but the Solunsky Christians took it and secretly interred it.
Under St. Constantine Equal to the Apostles, a church was erected over the grave of St. Demetrius. A hundred years later, during the construction of a new majestic temple, the incorruptible relics of the holy martyr were found on this site.
In Rus', veneration of St. Demetrius of Thessalonica began immediately after Epiphany. Temples and monasteries were built in his honor. On the icons he is depicted in military attire, with a spear and sword.
The Saturday before November 8 is called Dmitrievskaya Parents' Saturday, the day of remembrance of the dead.