Saint Cyriacus was born into a peasant family, and became a monk at the Tazlau Monastery. Since he surpassed the other monks in humility, prayer, and virtue, he was found worthy of the grace of the priesthood.
Wishing to attain further perfection, Saint Cyriacus withdrew to a mountain called Magura Tazlaului, where he lived for fifty years. There he struggled in a manner similar to the great hesychasts of old, sustaining himself with dried bread and fruits, keeping all-night vigils and shedding copious tears. Through the grace of the Holy Spirit, he was able to forsee future events, and to cast out evil spirits.
In time, many disciples flocked to him seeking spiritual counsel. These, in turn, became hesychasts and lived in the mountains of Tazlau, Nichitu, and Tarcau.
After he had reached a great age, Saint Cyriacus surrendered his soul to God around 1660. His disciples buried him in a cave on Magura Tazlaului, and many miracles were worked through his holy relics.
At the end of the seventeenth century Moldavia was threatened by great dangers, and many people took refuge in the forests. The relics of Saint Cyriacus were divided among the faithful so that they would not be profaned by infidels. Thus, the mountain cave on Magura Tazlaului was deprived of its great treasure.