This dissertation traces the long, winding, and problematic road along which marriage became a sacrament of the Church. In so doing, it identifies several key problems with marriage’s ability to fulfill the sacramental criteria laid out in Peter Lombard’s Sentences: that a sacrament must signify a specific form of divine grace, and that it must directly bring about the grace that it signifies. While, on the basis of Ephesians 5, theologians had no problem identifying the symbolic power of marriage with the spiritual union of Christ and the Church, they never fully succeeded in locating a form of effective grace, placing immense stress upon marriage’s status as a signifier. As a result, theologians and canonists found themselves unable to deal with several social aspects of marriage that threatened this symbolic capacity, namely concubinage and the remarriage of widows and widowers. For, just as concubinage possessed the dangerous ability to signify the one-to-one unity of Christ and the Church (and the pressure for exact symbolic conformity prevented theologians from imposing a formal marriage ceremony distinguishing the two), second marriages threatened to off-set the sacrament’s precarious numeric balance, wherein Christ and his heavenly bride are forever joined as two unique but entirely unified entities. This dissertation also contends that awareness of these problems was embedded in the larger medieval discourse about matrimony, and can be detected in literary depictions of marriage, marriage-making, and quasi-marital situations. It thus explores attitudes towards marriage in several prevalent literary genres, with an eye towards how each genre handles the sacramental problems outlined above. While the these literary treatments are all perceptibly impacted by the lacunae within sacramental discourse, they each display this impact in specific ways, depending upon social context and wider generic features and customs. In highlighting this discursive interplay, this dissertation finally seeks to illuminate the sense in which what we think of as “marriage” is a highly constructed conceptual entity, the result of much conversation, contention, and invention.