At the age of about nine in September 992 he rode out to receive the visit of his grandfather Sancho II, and escort him along the troop-lined road to his father at the az-Zahira court.
Following Al-Muzaffar's death, Sanchuelo first garnered the fealty of his brother's retainers, pending the Caliph's approval of his succession as hajib, which he subsequently received.
Just as they had done following the death of Almanzor, the population of Córdoba responded angrily to the continued domination of the ʿĀmirids over the sequestered caliph, with many also coming to believe that Abd al-Rahman had poisoned his brother.
The combination of his irreligiousness and incompetence, along with the prospect of the caliphate passing out of the hands of the north-Arab Umayyad dynasty and instead being vested in a representative of the Yemeni/south-Arab Ma'afiries who was also a grandson of a hated Pamplona king, led Córdoba's middle class and the general populace to oppose his status as crown prince, though he retained the support of the well paid mostly Berber and Slav army.
In the midst of this discontent, and in spite of having been warned by his son not to leave Córdoba because of a coup brewing among the Umayyad descendants of Abd al-Rahman III, Sanchelo nonetheless decided to launch a winter campaign in order to punish the fractious Christian kingdoms to the north, specifically León under their boy-king Alfonso V. Leaving his cousin Ibn Asqaleya in charge of the capital, he departed with his army in mid-January, only for his troops to become mired in snow, mud and floodwaters as Alfonso refused to give battle.
He named his cousin Abd al-Jabbar ibn al-Muguira to the office of hajib and sent him at the head of his supporters to Sanchuelo's residence of az-Zahira, which was immediately surrendered.
García encouraged him to abandon Córdoba and take refuge in the Christian north, but Sanchuelo was convinced that his presence near the city would cause his supporters to rise up and restore him.
Accompanied by the count's own men at arms, he set off toward the capital only to have his Berber army desert him, and on 3 March he reached Armilat, the last stop before the city, with just his own household, which included a harem of 70 women, and the Banu Gómez troops.
The success of Muhammad II encouraged other Umayyad scions and local lords to rise up, with the competitors each inviting the support from neighboring Christian states.