Truce Of God(Lat. treuga Dei or trewa Dei, from Ger. Treue, faith), an institution of the middle ages, designed to mitigate the violence of private war by prohibiting hostilities from Thursday evening to Sunday evening of each week, also during the entire season of Advent and Lent, and on certain festival days. The days of the week selected were supposed to be rendered holy by the death and resurrection of Christ. It was introduced after the great famine of 1028-'30, by the bishops of Aquitaine, who proclaimed a universal peace; as it was found impossible to enforce this, they were obliged to limit it to certain days, and thus arose the truce of God in its peculiar sense. The regulation soon spread over all France. In 1041 the Aquitanian bishops ordered that no private feuds should be prosecuted from sunset on Wednesday to sunrise on Monday following. This was extended by the council of Clermont to the time from Advent to Epiphany, from Lent to eight days after Pentecost (Whitsuntide), and afterward to the feasts of the Virgin, of John the Baptist, of the apostles Peter and Paul, and of All Saints, and the eves of those days.

Calixtus II., at the council of Rheims in 1110, renewed the truce of God, commanding war to cease on the above mentioned times throughout Christendom; all violators were to be excommunicated, and, unless satisfaction were given either by themselves or by their children, were to be denied a Christian burial. When the states of Europe began to assume a more consolidated form, and violations of peace and order came under the control of the civil authority, the truce of God disappeared.