Rom very ancient times the church and the churchyard have afforde'd refuge to villagers in time of war. For this reason, wherever practicable, churches have been built on heights, to be the more easily defended. The church served not only as a house of prayer but also as a protecting citadel, defending the lives and property of its children. Already in the 4th century the Armenians had made strong citadels of their churches. The Franks in Merovingian times (481-751) built fortified churches of which that of St. Jean at Poitiers still stands, as well as the church at Remainmontier. After the Saracen invasion most of the churches in the south of France were surrounded with defence works, whereas in northern France they were not defended before the English wars in the fourteenth century. In the Middle Ages most of the churches in the strip of land between the Rhine and the Nahe, called the Gau, were fortified. Osthofen had defence works as early as 1241. In the Middle Ages, too, fortified churches were built in Alsace and Lorraine, or else the existing ones were greatly strengthened. An especially characteristic example is Chazelles in Lorraine, built in the 12th century, in which we are first struck by the placing of the church-tower between the choir and the nave and then by the loop-holes and machicolations.