Why did the medieval church become involved with marriage? It seems, through my research, that the Christian Western marriage was created during the Middle Ages (cf. this question).

So, does that mean that before the Middle Ages, the Western Christian church did not really care about marriage? And if that is true, why and how did the medieval Christian church become involved with marriage?
Before the Middle Ages, the Western Christian church did not really care about marriage?


For most of Church history, matrimony had been celebrated without clergy and was done according to local customs. The first available written detailed account of a Christian wedding in the West dates only from the 9th century and appears to be identical to the old nuptial service of Ancient Rome. However, early witnesses to the practice of intervention by the clergy in the marriage of early Christians include Tertullian, who speaks of Christians "requesting marriage" from them, and Ignatius of Antioch, who said Christians should form their union with the approval of the bishop - although the absence of clergy placed no bar, and there is no suggestion that Ignatius' recommendation was widely adopted.

Over a period of centuries, the Catholic Church began to take control of the wedding and began to provide the sacrament of marriage. Taking the lead of Augustine (354-430), the Church developed the sacramental understanding of matrimony. James A. Brundage says, in Law, Sex, and Christian Society in Medieval Europe page 236, Gratian [the 12th-century "Father of canon law"] held that it was consummation that turned marriage into a sacrament, thereby making it indissoluble.

In time, the Church regarded a  clandestine marriage as being subject to annulment.  The  Catholic Church forbade clandestine marriage at the Fourth Lateran Council (1215), which required all marriages to be announced in a church by a priest. Prior to that time, an unwitnessed exchange of marriage vows was deplored but still valid. The decree was enforced only in those regions where it could be proclaimed in the vernacular. 

The Council of Trent (1545–1563) introduced more specific requirements, ruling that in the future a marriage would be valid only if witnessed by the pastor of the parish or the local ordinary (i.e., the bishop of the diocese), or by the delegate of one of said witnesses, the marriage being invalid otherwise, even if witnessed by a Catholic priest.