Alexander Grenkov was born on 21 or 23 November 1812 in the village of Bolshie Lipovitsy, in the Tambov Governorate. He was born into the family of a clergyman. Although he graduating from the theological school, he did not become a priest. He worked as a teacher, giving private lessons and teaching at the Lipetsk Theological School.
When he once fell seriously ill, he vowed that, if he survived, he would devote himself to the monastic life. However, he delayed fulfilling his promise and his conscience began to trouble him. In 1839, following the advice of Elder Hilarion, he arrived at the Optina Monastery, where he was received by the Elder Leo. He was soon tonsured as a monk and given the name Ambrose.
He was ordained a hieromonk and began serving alongside Father Macarius. However, before long, he fell ill again and his participation in the Divine Liturgy became limited. His illness nevertheless helped him deepen his spiritual life and his understanding of human nature. He continued his ministry as far as his health permitted it and eventually became a spiritual guide to the brotherhood, possessing a penetrating intellect and a remarkable ability to discern the souls of those who sought his counsel.
Elder Ambrose welcomed different people, helping them with both spiritual and practical matters. He taught them that illness can be beneficial for a monk. His advice was simple yet remained engraved in the memories of those who received it. During the final years of his life, he founded a convent at Shamordino.
In 1891, while staying there, he continued his work and ministry to the Church until his death on 10 (22) October. His body was transferred to Optina, where he was buried.
