Eymerich, Nicholas. Directorium Inquisitorum [Inquisitorial Directory]. With Commentary by Francis Pegña.

Roman Catholic theologian Nicholas Eymerich [Catalan Nicolau Aymerich] (c.1316-99) served as Inquisitor General of the Crown of Aragon. Eymerich was infamous for his torture of those suspected of heresy, earning him the enmity of King Peter IV of Aragon. Especially notorious was his brutal treatment of the Jew Astruc Dapiera of Barcelona in 1370 who was suspected of sorcery and sentenced to life imprisonment after publicly repenting. Eventually King Peter became so hostile to Eymerich—, who by then had begun persecutuion of the Llullists, (followers of the theologian Ramon Llull—), that Eymerich was forced to flee from Barcelona to Avignon, France. There in 1376, he composed his work Directorium Inquisitorum, in which, based on handbooks of witchcraft that he had confiscated, he described sorcery at great length. Directorium Inquisitorum became the handbook of Inquisitorial procedure well into the seventeenth century. See Y. Baer, A History of the Jews in Christian Spain (1966), Vol. II, pp. 86-87.