FELIX, bishop of Urgell. – In office at Urgell (c. 782) in the Hispanic March, d. in 818. Together with Elipando, he was the principal propagator of adoptionism, which he defended with great erudition and zeal. Condemned at the Council of Regensburg in 752, convened by Charlemagne, he publicly renounced his errors, which he once again abjured shortly thereafter in Rome before Pope Adrian I.
Having relapsed into the same errors, he wrote a most erudite work, now lost, which was later refuted by Alcuin, Paulinus II of Aquileia, and Agobard of Lyon. At a synod in Rome in 798, Leo III pronounced anathema against F. A public debate between F. and Alcuin before Charlemagne (Oct. 798) led F. to acknowledge his heresy. He then addressed a *Confessio fidei* to his fellow bishops of Urgell, urging them to adhere to the Catholic faith. Recently, the *Liber de variis quaestionibus adversus Judaeos ac ceteras infideles seu quoslibet haereticos*, previously falsely attributed to St. Isidore of Seville, has been identified as a work of F.