Name days on May 21
Konstantinos, Kostas, Kostis, Dinos, Konstandinos, Constantine, Costas, Costa, Gus, Konstantin, Eleni, Elena, Helen, Elli, Lena, Heleni, Konstantina, Constantina, Dina, Ntina, Kostoula, Helena, Ellen, Elenitsa, Nitsa, Lenio, Pachomios, Pachomius, Kassianos, Cassian
Saints and feasts of May 21

Constantine and Helen
Great Feast, Κωνσταντίνος και Ελένη
St. Constantine the Great, Equal-to-the-Apostles, was the first Roman Emperor to embrace Christianity. After his vision of the Cross and his victory under its sign, he ended the persecutions with the Edict of Milan, convened the First Ecumenical Council at Nicaea, and founded Constantinople as a Christian capital. His mother, St. Helen, traveled in old age to the Holy Land, where according to tradition she found the Precious Cross of the Lord and built churches on the holy sites.
Name days: Konstantinos, Kostas, Kostis, Dinos, Konstandinos, Constantine, Costas, Costa, Gus, Konstantin, Eleni, Elena, Helen, Elli, Lena, Heleni, Konstantina, Constantina, Dina, Ntina, Kostoula, Helena, Ellen, Elenitsa, Nitsa, Lenio
Pachomios the New Martyr
Martyr, Παχώμιος ο Νέος
Pachomios was born in Little Russia, captured by the Tatars and sold to a Turk in Ousaki in Asia Minor, where he served for many years without abandoning his faith. Freed, he became a monk on Mount Athos under the elder Joseph.
Kassianos the Greek
Venerable, Κασσιανός ο Έλληνας
Kassianos was a Greek nobleman named Constantine who came to Moscow in the entourage of Sophia Palaiologina. He became a monk at the Ferapontov Monastery and later founded a monastery near Uglich on the Volga.
Constantine of Murom with his sons Michael and Theodore
Saint, Κωνσταντίνος του Μουρόμ
Constantine was a prince of Kievan Rus who in the twelfth century was sent to rule Murom, then still largely pagan. His son Michael was killed by the pagans, and tradition relates that his patience and the wonders of an icon of the Theotokos won the people to baptism.
Christopher of Antioch
Hierarch, Χριστόφορος Αντιοχείας
Christopher was a Christian official who was chosen Patriarch of Antioch in the tenth century while the city was under Muslim rule. He was respected for his justice and his care for the Christians of the region.
Timothy, Polios and Eutychios
Martyr, Τιμόθεος, Πόλιος και Ευτύχιος
Timothy, Polios and Eutychios were deacons in the Roman province of Mauretania who preached Christ and were put to death for their faith. Few details of their martyrdom have been preserved.