In his relations with the Church, Charles gave a liberal interpretation to his acknowledged powers of guidance and direction; the kind of rôle he was willing to undertake shows that he drew no hard and fast line between the secular and spiritual prerogatives of a monarch. For example, in the Adoptionist Controversy, he took the initiative himself in settling a troublesome problem of theological speculation. According to the Adoptionists, in Christ there are a divine personality and a human personality, which latter becomes by adoption the Son of God. This tenet was eagerly embraced in Spain, its two best-known adherents being Elipandus, Archbishop of Toledo, and Felix, Bishop of Urgel, the latter a city in the North of Spain under the authority of the Frankish King, who, therefore, immediately took steps to bring the subject in dispute before a council, assembled at Regensburg, “under the orders of the most glorious and orthodox King Charles.” Felix was convicted of false teaching and sent to Rome to appear before Pope Hadrian. Though Felix was deprived of his bishopric he continued to be supported by the Spanish episcopate, who collectively wrote to Charles for his restoration. At Frankfort, in 794, a council of prelates from various Frankish sees met and listened to the King, who read the letter from the Spanish bishops. The council then heard a long technical speech from their ruler on the questions at issue. The Bishop of Urgel was again condemned, but the matter was not decided until a few years later, in 799, when a long discussion, lasting over six days, took place at Aix between Felix and Alcuin, the conclusion of which was that Felix allowed that he was overcome in argument, and published a retraction.