Anthony, John, and Eustathius were three kinsmen who served at the court of Algirdas (Olgerd), the pagan Grand Duke of Lithuania, in the city of Vilnius during the middle of the fourteenth century. According to the tradition recorded in the synaxarion, two of them, Anthony and John, were brothers, while the third, Eustathius, was their cousin. Born into the Baltic paganism then dominant in Lithuania, they embraced Christianity and were baptized, receiving their Christian names from a priest named Nestor. They are remembered as the first martyrs of Lithuania and are commemorated together on April 14.
The conditions for the spread of Christianity in Vilnius had been favored during the lifetime of Maria Yaroslavna, the Orthodox wife of Algirdas, who died in 1346. After her death, the tradition relates, the pagan priests pressed the Grand Duke to suppress the Christian faith, and a persecution of the small Christian community began. The three kinsmen did not openly flaunt their religion, but neither would they conform to pagan custom: they did not cut their hair in the manner of the pagans, and on fast days they declined the foods their faith forbade. These outward signs of their Christianity drew the attention of the persecutors.
By tradition the three were arrested and, when they refused to renounce Christ or to abandon Christian observance, were put to death by hanging. The synaxarion relates that they suffered upon a single oak that afterward became revered among Orthodox Christians, and that a church dedicated to the Holy Trinity was later raised on the site of their martyrdom, its altar built upon the stump of that oak. Their relics were venerated as incorrupt; in modern times they were carried to Moscow in 1915 amid the upheavals of war and returned to Vilnius in 1946, where they are enshrined in the Monastery of the Holy Spirit.