There were several reasons for prohibiting a marriage. One reason was consanguinity, meaning the couple was too closely related. If the boy or the girl had taken a monastic or religious vow, the marriage was than also prohibited. Other reasons that prohibited marriage, but were not grounds for a divorce, were rape, adultery and incest. A couple could also not be married during a time of fasting, such as lent or advent, and a couple not be married by someone who had killed someone.