Abelard discussed the status and history of the ordo sanctimonialium in several of his works. In them he identified abbesses as the successors to the ancient order of deaconesses and thus sacramentally ordained and equal to any male order. This understanding followed a venerable tradition that stood in stark contrast to the more recent claims of the Glossa ordinaria, Gratian and Peter the Lombard that the only true sacramental orders were the subdiaconate, the diaconate and the presbyterate. Abelard's work then can be understood in part as a response to these claims and a defence of the older tradition.