This 14th century Inquisition Post Mortem is dated 1315. Five Agnus Dei and three Sanctus in Ars nova notation have been added on the blank space at the back at a later date.
INVENTORY
Répertoire international des sources musicales. BIV 2. Manuscripts of Polyphonic Music (c.1320-1400), edited by Gilbert Reaney, G. Henle Verlag: Munich-Duisburg, 1969, pp. 242-245.