This chapter examines the self-consciousness about ‘special’ liturgical and ceremonial practices in one of the most emblematic female communities of medieval Europe, the Royal Abbey of Las Huelgas in Burgos. The recently re-discovered monastic ceremonial of Las Huelgas offers us invaluable insights into the self-regulation of the conventual liturgy held at the royal abbey. Written in the vernacular Castilian, this ceremonial was compiled by the nuns themselves around 1400 with a view to ensuring the continuity of the community’s special customs. The manuscript thus showcases the community’s effort to preserve its autonomy by keeping control of their own liturgical practice, and uncovers the extent to which the nuns assumed active roles in the performance of conventual liturgy. The female voice of this ceremonial is especially evident in the use of feminine pronouns and verb-endings. The text prescribes Mass celebrations held by the abbess and her convent, as well as the nun’s performance of three-part polyphony.