Title: De vier vrienden
Subjects: Companions, Caliphs, Biography
People: Muḥammad Prophet (-632), Abū Bakr Caliph (-634), ʻUmar ibn al-Khaṭṭāb Caliph (-644), ʻUthmān ibn ʻAffān Caliph (-656), ʻAlī ibn Abī Ṭālib Caliph (approximately 600-661)