Broadly speaking, some of the moral dilemmas facing the Catholic hierarchy and the Catholic faithful today are the issues of co-habitation, marriage as covenant vs. contract, and same-sex marriage. The idea of marriage as well as the institution of marriage in the Western world itself has a colorful, complicated, and tortuous past from ancient antiquity, through the Middle Ages, to the present. The Middle Ages are the most important period in the evolutionary history of modern marriage because it was the Catholic Church that was instrumental in developing the culture of the modern age through its clergy and through their pastoral and educational institutions till the present in the Western world. On account of the enormity and complexity of the subject of marriage, I shall briefly and necessarily in a sketchy manner look only at thirteen relevant aspects in the evolution of the institution of marriage the Church had to deal with in the past and still tendentiously contends with today with no easy answers.