He was invested with authority over the cities of al-Andalus in 238 AH, immediately after his father.
He campaigned incessantly, pushing deep into Byzantine lands and remaining on expedition for a year—sometimes two—engaged in fighting and the taking of captives.
Al-Hafiz Baqi ibn Makhlad said, “I have never seen, nor do I know of, any king whose speech is more persuasive than that of Prince Muhammad ibn ʿAbd al-Rahman—none more eloquent or more clear-thinking than he.”
Sibt Ibn al-Jawzi adds that he was the commander at the battle of Salit (1), a colossal encounter in which, it is said, three hundred thousand unbelievers were slain—a number the like of which has never been heard—and the poets extolled him (2).
He died in Safar 273 AH. After him his son al-Mundhir (3) assumed power, but his days were few.
(1) Al-Bayan al-Mughrib, vol. 2, pp. 168-169, records the battle of Wadi Sulayt as follows: “Abu Umar al-Salmi said: This was his first incursion into enemy territory; he assembled troops, organised them as he wished, and found that the enemy’s cavalry had already occupied the wide plain, both near and far, ready to confront him. At that moment, fear seized Emir Muhammad; panic mixed with terror, and he thought there was no escape from the unbelievers and that the Muslims would be fodder for their swords. He therefore judged it safer and more prudent to withdraw, invoking the verse: wa-la tulqu bi-aydikum ila at-tahlukah (Do not cast yourselves into destruction, Qur’an 2:195). A man then rose and said: ‘Emir, God says: alladhina qala lahum an-nas inna an-nasa qad jamaʿu lakum … (Those to whom the people said: “The people have gathered against you…”, 3:173).’ Emir Muhammad replied: ‘By God, what concerns me is that there is no judgment for one who is not obeyed, and I cannot fight alone.’ Al-Utbi said to him: ‘By God, no one placed those words on his tongue except an angel. Perform istikhara tonight and tomorrow.’ God then showed him right guidance, resolve, success, and steadiness. He summoned the people to confront the enemies of God and to champion His religion, each one convinced of certain victory. When the banners were raised and their determination for combat confirmed, Emir Muhammad placed his son al-Mundhir—renowned for bravery and beloved among the people—at their head. The Muslims advanced until the two armies met and clashed; God granted His allies triumph and victory, and after hardship He brought ease.”
(2) For assessments of him, see al-Bayan al-Mughrib, vol. 2, p. 166 ff.
(3) His biographical reports are collected in al-Bayan al-Mughrib, vol. 2, pp. 170-181.