During the religious wars of the sixteenth century, St. Lo was once more so unfortunate as to act a prominent part. Early in the troubles, it distinguished itself by a decided devotion to the cause of Protestantism; and, though often obliged, by the current of affairs, to yield a reluctant submission to the opposite party, it continued throughout the whole of the struggle, unshaken in its attachment to the Huguenots. Hence, when finally summoned to surrender to the Catholics, in 1574, it rather chose to expose itself to all the miseries of a siege, as well as to the still greater one of being taken by assault; and the severity of its sufferings is recorded by the historians of the conquering party, who themselves admit, that "it was sacked with a horrible carnage."[195] Its Protestant places of worship were not, however, finally rased, till 1685, the period of the revocation of the edict of Nantes. St. Lo was the seat of an abbey of Augustine friars, said to have been founded in the middle of the twelfth century, and to have been of such celebrity, that, according to Quercetanus, the bishops of Coutances were contented for a time to be styled bishops of St. Lo.[196]The principal church in the place, that of Notre Dame, greatly resembles the cathedral of Coutances, of which it is even said to be a copy. It was not begun to be built till the period of English rule in Normandy, during the fifteenth century. The older, or clock-tower, was erected in 1430: the opposite tower and western entrance, in 1464. Other parts of it were not completed till the following century; and the northern spire is a work of as late a period as 1685.