History of Islam - Umar Ibn al-KhattabA Reader Series Umar Ibn al Khattab Rightly Guided Khalifah History of Islam The age of the rightly guided caliphs Al Khulafa Ar Rashidun This is the second volume from this series, which deals with the life of Umar ibn al Khattab (ra), the second of the Four Rightly Guided Caliphs. The evaluation of Amir al Mu'minin Umar al Farooq, may Allah be pleased with him, and his far sighted policies is captured in a statement attributed to the Prophet (S),