Muhammad I Abu 'l-Abbas
Muhammad I was the son of the fourth emir, Abu Iqal (838–841). Under him the Aghlabids continued their expansion into the Mediterranean, conquering Taranto and Bari (841) in Apulia and Messina in Sicily (843). In 846 an Aghlabid force seized Rome and plundered the Vatican, though they were not able to hold on to Rome and Taranto and Bari soon detached themselves from the Aghlabids and submitted to the Abbasids in Baghdad.
In Ifriqiya agriculture and trade flourished and there was new urban construction, notably of the Great Mosques of Sousse and Sfax. Muhammad's reign was briefly interrupted by the usurpation of his brother Abu Ja'far Ahmad, who like his Abbasid contemporary Al-Wathiq supported the Mu'tazili and persecuted their Sunni opponents, executing some and imprisoning others, like the Maliki jurist Sahnun; when Muhammad I regained the throne in 847, he sent his brother into exile and rehabilitated the Sunnis, making Sahnun chief qadi of Ifriqiya.
Muhammad I was succeeded by his son Ahmad ibn Muhammad (856–863).