Códice de las Huelgas is a musical manuscript or codex from around 1300 that originated and was preserved in the Cistercian monastery of Santa Maria la Real de Las Huelgas in Burgos.
The manuscript contains 45 monophonic pieces 20 sequences 5 Benedicam conducti 10 tropes and 141 polyphonic compositions.
https//es.wikipedia.org/wiki/Códice_de_las_Huelgas
https//en.wikipedia.org/wiki/Las_Huelgas_Codex