Recemundus, a Mozarabic cleric, is sent by the caliph on a diplomatic mission to the court of Otto I the Great of Germany, to normalize relations with the Holy Roman Emperor, the most powerful Christian ruler in western Europe. Recemundus later authors the Calendar of Córdoba, a valuable compendium of agricultural practices in Al-Andalus. John of Gorze, a monk and diplomat, visits Córdoba on behalf of Otto II a few years later.