- Author: Lev Nikolayevich Tolstoy
- Copyright: Public domain
- Published in: 1873
- Word count: 17,634 words (≈ about 1 hour)
"Father Sergius" is a short story written by Leo Tolstoy between 1890 and 1898 and first published (posthumously) in 1911. The story begins with the childhood and exceptional and accomplished youth of Prince Stepan Kasatsky. The young man is destined for great things. He discovers on the eve of his wedding that his fiancée Countess Mary Korotkova has had an affair with his beloved Tsar Nicholas I. The blow to his pride is massive, and he retreats to the arms of Russian Orthodoxy and becomes a monk.