During the First World War, French soldiers could get married without being present at the wedding. In fact, a law passed on 4 April 1915 authorized marriage by proxy. This law was exceptional but temporary: First, it was enacted solely during the period of the war; secondly, it put the couple in the middle of the stake of conflict. On the one hand, it was supposed to ease the passage of separation of the estranged couples; on the other hand, it had to favor the good spirits of the soldier and to take part in the politics of the country at war; lastly, its objective was to safeguard the institution of marriage and family by allowing, such ceremonies despite upheavals and separation. However, the proceedings and discussions about marriage by proxy revealed the existence of free unions which threatened the marital structure. In addition, the reform disturbed the elementary rules and normal procedures of the celebration of the 'sacred duty'. Moreover, legislators were confronted with the slaughter of the first months of the war and so they voted the law in haste: urgency thus taking the step over effectiveness. In conclusion, for all these reasons, the law of April 4, 1915, which was considered a failure, shook and weakened the institution it was supposed to protect.