Leidradt a noted Poman Catholic prelate, probably a Bavarian flourished in the 8th century. He was librarian to Charlemagne until 798, when he was made archbishop of Lyons. He was sent soon after by Charlemagne, together with the bishop of Orleans and other prelates, into the southern provinces of France, to suppress by moral means the spreading heresy of Adoptianism, and they succeeded in bringing the chief teacher of this doctrine, Felix, to acknowledge his error before the council held at Aix in 799. In 800 Leidradt was successful with his co-laborers in restoring 20.000 Adoptianists. He zeal which he everywhere displayed appears in a letter written to Charlemagne not long before the latter's death. He writes: "I have done my best to increase as far as necessary the number of priests. I have established the Psalm service after the model of that observed in your palace, and have erected singing-schools by which the instruction may be continued. I have reading-schools where not only the appointed services are repeated, but where the holy Scriptures in general are studied and explained, and in which are those who understand the spiritual meaning not only of the Gospels, but also of the prophets, the books of Samuel, the Psalms, and Job. I have had as many books as possible transcribed for the churches in Lyons, procured vestments and other necessary appointments for divine service, and have repaired the churches." After Charlemagne's death, in the subscription to whose will the name of Leidradt appears, he resigned the bishopric and retired to the convent of the Holy Medardus. where he died. Neither the year of his death nor of his birth are known. He wrote in a clear and concise style some works which have since been edited. Of special value is a treatise of his on baptism, which was published by Mabillon (Annales, vol. 2). See Herzog, Real-Encycklop. art. Baluze; Wetzer u. Welte, Kirchen-Lex. vol.6i, s.v.