The Church of St. Mary in Bethlehem or, as it is more commonly called, the Church of the Nativity, was built about the year 330, during the reign of the Emperor Constantine; and, as we have already seen, a very ancient tradition ascribes its erection to the emperor’s mother, St. Helena. Through all the wars which have raged over Palestine and during which the city of Bethlehem has again and again been devastated and its houses and castles and monasteries overthrown, the old church alone has escaped destruction. It is no wonder that its preservation has so often been ascribed to miraculous interventions. Although the building has been slightly altered and restored from time to time, its essential features have not been changed, and there can be little doubt that this is the oldest church in the world. Except for the single low belfry, the heavy, confused mass looks more like a fort than a religious edifice. Besides the central church, there lie practically under the same roof three large monasteries, belonging to the Greek Orthodox, Gregorian Armenian, and Roman Catholic communions. The collection of buildings is at the extreme eastern end of the town, so that while the front faces the public square of Bethlehem, the rear is at the very edge of a steep cliff, below which stretches the open country. Viewed from the east, the massive pile resembles a great feudal castle overlooking the farm lands of the vassals in the valley beneath. There are very few windows in the thick stone walls, and the main entrance from the square is by a single narrow door, so low that one must stoop in passing through. The two other doorways at the front have been walled up and this one purposely made so small, for fear of attack by the Moslems. Yet to-day we find just inside the vestibule a half-company of Turkish infantry. It seems strangely incongruous that Moslem soldiers should be encamped in a Christian church, but we shall see later that there is a good reason for their presence here. [Illustration: INTERIOR OF THE CHURCH OF THE NATIVITY Showing the high stone wall which separates the nave from the choir and transepts]