Abu Bakr ibn Umar al-Lamtuni was the Sanhaja war-leader of the Almoravid movement, standing beside Abdallah ibn Yasin as the commander to the founder's spiritual authority. When the movement divided he took the southern, desert wing, the veiled Lamtuna and Masufa of the Sahara, while his kinsman Yusuf ibn Tashfin carried the conquest north into Morocco and al-Andalus. In the saga literature of the western Sahara he is preserved as an ancestral culture-hero of the Bidan, and later tradition set his grave in the desert country of the Adrar and Tagant, marking him as a founding forefather of the Saharan tribes. He died in 1087, struck by a poisoned arrow while campaigning in the lands of the Sudan.