Abū Yaʿqūb, Yūsuf b. ʿAbd al-Muʾmin b. ʿAlī (533–580/1139–1184), was the second Almohad caliph of the Maghrib and al-Andalus. His ancestry went back to the famous tribe of Qays ʿAylān (a large north Arabian subdivision of Muḍar) (Ibn ʿIdhārī, 3/56; Ibn Khaldūn, Yaḥyā, 1/170). His father ʿAbd al-Muʾmin was the first caliph of the Almohads and one of the ‘ten companions’ of Ibn Tūmart, while his mother ʿĀʾisha (or Zaynab) was the daughter of Mūsā b. Sulaymān, the qāḍī Ibn ʿ…