He was a member of the Umayyad dynasty of Al-Andalus (Moorish Iberia), the son of Muhamad bin Abd al-Rahman.
Born in Córdoba, during the reign of his father he commanded the military operations against the neighbouring Christian kingdoms and the Muwallad rebellions.
On his way back to Córdoba, he defeated Rodrigo, count of Castile, at Burgos, pushing the Cordoban frontier northwards.
Al-Mundhir launched an expedition against the Banu Qasi Muwallad family, who had allied with Alfonso III, but was again defeated in 883.
He died in 888 at Bobastro, possibly murdered by his brother Abdullah ibn Muhammad al-Umawi, who succeeded him.