On 4 August 1029, Adémar departed Limoges in disgrace and returned to his home abbey of Saint Cybard in Angoulême. There, he spent the next few years compiling the forgeries he hoped would eventually provide incontrovertible evidence of Martial's apostolic status. The most notable among these are the proceedings of the Council of Limoges in 1031 and the letter from Pope John XIX, both of which survive in Adémar's autograph and unequivocally endorse Martial as an apostle. He also devoted some of his time to the production of music manuscripts, as the fragmentary antiphoner in the endpapers of Pa 1978 and the addition to Pa 1118, discussed in Chapter 2 above, show. As well, he altered the liturgy for Martial in Pa 1120 and 1121. He passed his last years at Saint Cybard friendless in lonely isolation.

When he resolved to quit this difficult situation in Angoulême and to assuage his guilt by embarking on pilgrimage for Jerusalem, he decided to leave his library behind at Saint Martial. There, some years after his death, a sympathetic monk entered the following colophon in the most elaborate codex he had produced, Lei 8° 15.