The feast day of St Margaret of Antioch (20 July) was observed almost universally in the liturgical calendar. Witnesses of the Sarum Ordinal prescribe without variation the observance of Margaret’s feast with texts taken from the Common of Saints, including a procession to an altar of St Margaret. However, there are several Office books extant which preserve complete sets of coherent and well-crafted Proper texts for Margaret. Despite its unlikely and scant survival rate, this Office for Margaret, which survived the imposition of contradictory instructions in the Ordinal, was not haphazardly created or transmitted: it demonstrates how a saint’s legend recognised as potentially spurious at an early stage could be interleaved with a familiar liturgical framework of psalmody and sung texts.