Have you ever wondered why some churches have such lovely porches? It's almost as if they were made for people to stand under. Well, you wouldn't be far from the truth on that assumption. In the 1200s weddings did not take place inside the church but at the church door, hence the lovely porches so the people attending the wedding could shelter if it rained.
So, at the door of the churh, the happy groom would give his wife to be something symbolic, such as a knife. At the end of this doorstep ceremony, the couple were pronounced man and wife and were free to proceed into the church, prostrate themselves at the altar, followed by the wedding party, and hear mass. While prostrated, the altar cloth would be held over the newlyweds. At the point when they received communion, the husband would give the priest a kiss, the kiss of peace, and only after that would he give his glowing bride a kiss. (Note the bride did not have to kiss the priest).
According to the Church in those days, what gave validity to a marriage was the free exchange of vows between a man and a woman, who were both over the age of twelve. Because of this, the wedding did not even have to take place at the church door, or in fact anywhere near it, as vows could be exchanged in the house, in the garden, or even in bed. (I know where I would have prefered to exchange them...)