The third book in the "History of the Caliphate" series is dedicated to the third righteous caliph 'Uthman ibn Affan - the best of the companions after Abu Bakr al-Siddiq and 'Umar ibn al-Khattab. The author tried to show his personality from different sides so that the reader gets the most complete picture of this great man. And the source of this greatness was his understanding and practical application of Islam - the religion of the Almighty, his inextricable connection with the Lord and unswerving adherence to the Sunnah of the Messenger of Allah. If Abu Bakr was a man of a gentle disposition, distinguished by his determination, and 'Umar was demanding and unpretentious, then 'Uthman was distinguished above all by his diplomacy and desire to achieve agreement. The reign of 'Uthman ibn 'Affan was marked by a significant expansion of the boundaries of the Caliphate and the strengthening of state institutions established by his predecessors - the righteous caliphs Abu Bakr al-Siddiq and 'Umar ibn al-Khattab. 'Uthman is one of the ten who rejoiced at the good news of Paradise and is one of those people whose words and deeds are a wonderful example for us. Familiarization with the biography of 'Uthman ibn 'Affan helps strengthen the faith of any Muslim and teaches believers to correctly understand their religion. The book will also be useful for those who are interested not only in the personality of the third righteous caliph 'Uthman ibn 'Affan, but also in the historical era in which he lived .