On May 21 each year, Orthodox Christians pay homage to two of the most venerated saints – the equal-to-the-apostles Constantine and Helen. The rule of Constantine I was a turning point in the advancement of the Christian Church. He was the first Roman emperor to adopt Christianity. Due to his huge contribution to Christianity, he was later called Emperor Constantine the Great.

In AD 313, Emperor Constantine issued the famous Edict of Milan that recognizes Christianity as an allowed religion. The greatest deed of Saint Constantine’s mother, Saint Helen, was that during her pilgrimage to the Holy Lands, she found the relics of the True Cross which was buried on the Golgotha hill. The mission of the Holy Saints Constantine and Helen is of huge importance to all Christians since it put an end to the bloody persecutions against Christians within the Empire and enabled the spread of Christianity in Europe.

Emperor Constantine very much liked the ancient town of Serdica, present-day Sofia. He came here often and lived for months in his residence that took a whole quarter in downtown present-day Sofia. He loved to say: “Serdica is my Rome”.

There are also many churches in Bulgaria named after the Holy Saints Constantine and Helen whose feast day is marked every year on May 21. 

In some parts of the Standja Mountain, the day of Saints Constantine and Helen is connected to the folk ritual of nestinarstvo (dancing on burning embers) as the dancers hold an icon of Saints Constantine and Helen. The ritual has never been recognized by the Bulgarian Orthodox Church but in 2009 it was included in the UNESCO World Heritage List.