The buildings on the site have been so repeatedly ruined and rebuilt, and so little remains now of their original features prior to the Crusaders’ work, that it is only necessary here to state the generally accepted belief that the rotunda (A) shown on the upper part of the plan (Woodcut No. 536) represents the position of the great apse erected by Constantine, round what he considered to be the sepulchre of Christ (marked B on plan). The great basilica which is described by Eusebius,[10] was erected on the east side of this. This and other buildings were destroyed by Chosroes the Persian in 614, and portions only (those round the Holy Sepulchre) were restored by Modestus in 629. In 1010, the mad Khalif Hakem destroyed Modestus’s work, and the rotunda, as shown in Woodcut, was built by the Emperor Constantine Monomachus thirty years later. [Illustration: 536. Plan of the Church of the Holy Sepulchre. Scale 100 ft. to 1 in.] When the Crusaders reached Jerusalem, 1099 A.D., the sepulchre appears to have stood in a court open to the sky,[11] but “covered over lest rain should fall upon it,” surrounded with an aisle and with five chapels (C.D.E.F.G.) attached to it. These the Crusaders incorporated[12] with their additions and alterations, which amounted almost to a rebuilding of the church. The plan (Woodcut No. 536) indicates in black those portions found by the Crusaders; in half tone, those which were built by them, and in outline only the subsequent additions made before and after the great fire of 1808.[13] Though entirely at variance with the arrangement of the basilica and independent tomb-house as adopted by Constantine some seven centuries earlier, it would seem that the object of the Crusader was to preserve intact the Rotunda and the Holy Sepulchre. The principal entrance led into what was virtually the main transept, with the Rotunda on the west side and the choir and apse on the east. At a later period the space within the crossing was enclosed for the Greek Church, so that the Rotunda now appears to be the nave, and it is in that sense that the church has been so often copied. The plan was commonly employed in the North of Europe (Woodcuts Nos. 790 to 795), and bloomed into perfection at Cologne in the church of St. Gereon (Woodcut No. 741). It is also found at Little Maplestead (Woodcut No. 847), Zara (Woodcut No. 486), in the churches of the Temple in London, of St. Sepulchre at Cambridge, and elsewhere. In all these instances it consists of a circular nave leading to a rectangular choir terminated by an apse. Though primarily sepulchral in its origin, it is used in all these places without any reference to its original destination, and had become a recognised form of Christian church for the ordinary purposes of worship.