Saint Nicholas Svyatosha, Prince of Chernigov and Wonderworker of the Kiev Caves (~ 1080 - October 14, 1143) was the first Russian Prince who became a monk. Born as Svyatoslav, was baptized as Pancratius. His memory is celebrated on October 14.
Saint Nicholas was a son of Prince David Svyatoslavich of Chernigov, grandson of Prince Yaroslav Svyatoslavish of Kiev and Chernigov and great-grandson of Great Prince Yaroslav the Wise. Nicholas was the Prince of Lutsk, and he had a wife and children (his daughter was later married to the Prince St. Vsevolod-Gabriel of Novgorod).
After the death of his wife, Nicholas arrived to the Monastery of the Kiev Caves and was tonsured a monk in 1107. Then he went through several kinds of obedience: for 3 years in the kitchen, for another 3 years at the gate, and then in the refectory. Then he took upon himself the vow of silence. He built a garden near his cell and was always doing something, constantly reciting the Jesus Prayer. He never took any food except the common monastic meal, and only in small amount. If he, against his will, as the prince had to get something from the people, then he immediately distributed it for the needs of pilgrims and poor people and for the needs of the church. Many books were purchased for the church at his expense. Nicholas was also an avid peacemaker. In 1142 he reconciled the great princes of Chernigov with Prince Vsevolod.
When Nicholas was a Prince, he had a skilled doctor by the name of Peter. Peter often visited Nicholas in the monastery and advised to abandon such severe way of life. Once Peter became ill. Nicholas sent him a message: "If you do not take any medicine, you will soon get better. Otherwise you will suffer for a long time". Peter did not obey, took the medicine and almost died. Then he was cured by the prayers of Nicholas.
Later, when Peter became ill again, he obeyed Nicholas saying: "Do not undergo medical treatment and in 3 days you will be cured". When he was cured, he came to Nicholas who said: "Peter! You ought to become a monastic, and instead of me to work in the monastery for the Lord and His Blessed Mother, because I will leave this world in 3 months". When Nicholas showed to Peter the place that he prepared for the grave, Peter, due to much love to him, started to ask him: "I know, that if you want, you can ask the Lord to allow me to die instead of you". Then Nicholas advised Peter to take monastic vows and pray for 3 months to get to know the Lord's will.
When 3 months passed, Nicholas asked Peter again: "Do you want me to take you with me?" Peter replied: "I want you to allow me to die instead of you and you will stay here and pray for me". Nicholas said: "Be of good cheer and get ready, because as you wished, on the third day you will leave this life". Peter took the Holy Communion and reposed while Nicholas lived for another 30 years and reached holiness according to his nickname (Svyatosha). When he died, the whole Kiev gathered at his burial.
After the death of Nicholas, his brother Prince Izyaslav became severely ill. The abbot of the monastery sent the water form the coffin of St. Theodosius and St. Nicholas' hairshirt. Izyaslav took the water, put the hairshirt on and was healed. Later, every time Prince Izyaslav became ill, he put on this hairshirt and soon got well. He also used to put on this hairshirt when was going to a war. Once Izyaslav committed a sin so that he did not dare to put on the hairshirt before the war. That time he was killed on the war. But beforehand, he ordered to be buried in this hairshirt.