to include the liberal arts, and most importantly, the study of religion. From 782 to 790, Alcuin taught Charlemagne himself, his sons Pepin and Louis, as well as young men sent to be educated at court, and the young clerics attached to the palace chapel. Bringing with him from York his assistants Pyttel, Sigewulf, and Joseph, Alcuin revolutionised the educational standards of the Palace School, introducing Charlemagne to the liberal arts and creating a personalised atmosphere of scholarship and learning, to the extent that the institution came to be known as the 'school of Master Albinus'. In this role as adviser, he took issue with the emperor's policy of forcing pagans to be baptised on pain of death, arguing, "Faith is a free act of the will, not a forced act. We must appeal to the conscience, not compel it by violence. You can force people to be baptised, but you cannot force them to believe." His arguments seem to have prevailed – Charlemagne abolished the death penalty for paganism in 797. Charlemagne gathered the best men of every land in his court, and became far more than just the king at the centre. It seems that he made many of these men his closest friends and counsellors. They referred to him as 'David', a reference to the Biblical king David. Alcuin soon found himself on intimate terms with Charlemagne and the other men at court, where pupils and masters were known by affectionate and jesting nicknames. Alcuin himself was known as 'Albinus' or 'Flaccus'. While at Aachen, Alcuin bestowed pet names upon his pupils – derived mainly from Virgil's Eclogues. According to the Encyclopædia Britannica, "He loved Charlemagne and enjoyed the king's esteem, but his letters reveal that his fear of him was as great as his love." Return to Northumbria and back to Francia In 790, Alcuin returned from the court of Charlemagne to England, to which he had remained attached. He dwelt there for some time, but Charlemagne then invited him back to help in the fight against the Adoptionist heresy, which was at that time making great progress in Toledo, the old capital of the Visigoths and still a major city for the Christians under Islamic rule in Spain. He is believed to have had contacts with Beatus of Liébana, from the Kingdom of Asturias, who fought against Adoptionism. At the Council of Frankfurt in 794,