Sworn Book of Honorius (Liber Juratus Honorii)

One of the oldest and most influential of all medieval grimoires on ceremonial magic. The Liber Juratus claims to be a collection of sacred wisdom preserved by a council of 81 magicians under the direction of 'Honorius of Thebes' in response to church persecution. It focuses heavily on theurgy (divine magic), specifically the 'Seal of God' (Sigillum Dei Aeth) and the rituals required to obtain the 'Vision of God'. The work is characterized by its high ritual complexity, including long periods of prayer, fasting, and the invocation of vast hierarchies of celestial and infernal spirits. It served as a primary source for John Dee's later Enochian operations.