Sa'dun al-Ruayni (Arabic: سعدون الرعيني) was Governor, or Wali, of Barcelona from 792 to 801 and the penultimate Muslim ruler of the city.
[1] He was appointed successor to Matruh ben Sulayman al-Arabi in circa 792 by the Emir of Córdoba, Hisham.
However, in 796 he led a revolt against the Emir; in April 797 he travelled to Aachen and offered Charlemagne the city's loyalty in exchange for the empire's help against Córdoba.
Charlemagne summoned an assembly in Toulouse in the spring of the 800 which agreed to send an expedition led by his son Louis the Pious to Barcelona.
However, on arriving at Barcelona, Sa'dun, who had in the meantime been reconciled to the Caliphate, refused to open the city gates.