Son of the previous caliph, Muhammad al-Nasir, the ten-year-old Yusuf was unexpectedly appointed heir by his father on his deathbed. He was confirmed as Almohad Caliph in election by the Almohad sheikhs after his father’s death, and took up the caliphal title "al-Mustansir" ("he who seeks the aid of God"). Yusuf’s mother was a Christian slave Qamar.
It can also refer to Yusuf II, Sultan of Granada. Abū Yaʿqūb Yūsuf al-Mustanṣir (also known as Yusuf II, c1203–1224) (Arabic: يوسف بن الناصر Yūsuf bin an-Nāṣir) was Caliph of Morocco from 1213 until his death. But without central leadership, and with the Almohad army having suffered grievous losses at the Battle of Navas de Tolosa in 1212, a series of rebellions broke out in the Maghreb which the Almohad oligarchs were hard-pressed to contain, contributing to the eventual breakaway of Ifriqiya under the Hafsid dynasty.
Yusuf II died suddenly in early 1224 - accidentally gored while playing with his pet cows. Lacking heirs, the palace bureaucrats, led by Ibn Jam'i, quickly engineered the election of his elderly grand-uncle as the next caliph Abd al-Wahid I, as the new caliph in Marrakesh. They promptly disputed the succession, and elected their own Caliph Abdallah al-Adil.
Yusuf had three viziers in the first year of his reign:
Abu Sa'id Uthman ibn Jam'i (1214) (also vizier to Muhammad an-Nasir)
Abu Yahya al-Hizraji (1214) (أبو يحيى الهزرجي Abū Yaḥyá al-Hizrajī)
Abu 'Ali ibn Ashrafi (1214) (أبو علي بن أشرفي Abū ‘Alī b Ashrafī)
Abu Sa'id Uthman ibn Jam'i (again) (1214–1223)
Abu Sa'id Uthman ibn Jam'i would also serve as vizier to Abdul-Wahid I.
