The Corpus Christi play in sixteenth-century Spain evolved as it did because poets were consciously searching for a dramatic formula which should be appropriate to a sacramental play. The idea of a sacramental play, an auto sacramental, was new at that time. A sacramental drama had never before been attempted, either in Spain or elsewhere. Corpus Christi was celebrated, in. Spain as in Europe at large, with performances of mystery-type plays derived from the tropes of the liturgy. The earliest Corpus plays in Spain were Nativity plays which dramatists scarcely troubled to adapt. As the problem of making the Christmas play appropriate to Corpus Christi forced itself on the attention of dramatists a new idea of religious drama emerged.