Boisserée places in this age the original cathedrals of Fulda and Cologne, both which he assumes to have been double-apse basilicas, but apparently without any sufficient data. There is no doubt that the cathedral at the latter place, burnt in 1248, was a double-apse church; but if it was anything like his restoration it could not have been erected earlier than the 11th or 12th century, and must have replaced an older building, which, for anything we know, may have been circular, as probably as rectangular; and such would likewise appear to have been the case at Fulda,[63] though there is as little to reason upon there as at Cologne. [Illustration: 693. View of West End of Church at Gernrode. (From Puttrich.)] There can be little doubt that the church of St. Justinus, built by Archbishop Otgar, 826-847 A.D., at Höchst (between Mayence and Frankfort) is of the Carlovingian period, as also parts of the church of St. Castor at Coblenz, and the churches at Michælstadt and Seligenstadt, the two last erected by Eginwald, the biographer of Charlemagne. The most important building of the tenth century is the crypt of the Abbey of Quedlinburg, erected by Matilda, consort of Henry I., in 936 A.D. It consists of three aisles, covered with parallel barrel vaults supported upon alternating piers and columns, and is the first appearance of this favourite form of support in German basilicas. The dimensions of this building are 23 feet 8 inches × 22 feet 7 inches, and 32 feet 2 inches to the crown of vault. The caps and bases take a distinctive form, leading from the debased Roman to the Romanesque, the further development of which can be seen in the choir of the abbey church at Essen, erected shortly after 947 A.D. Leaving these, we must come down to the end of the 10th or beginning of the 11th century for examples of the class we are now speaking of. Of these, one of the most perfect and interesting is the church at Gernrode, in the Hartz, founded A.D. 960, when probably the eastern part (not the extended choir) was commenced, and the whole building may be assumed to have been erected within a century after that date. From the plan (Woodcut No. 692) it will be seen how singularly like it is to the St. Gall example, except that it appears to have been originally about 50 ft., or one-fourth, less in length. The western circular towers, instead of being detached, are here joined to the building. Piers too are introduced internally, alternating with pillars; and altogether the church shows just such an advance on the St. Gall plan as we might expect a century or so to produce. It exemplifies most satisfactorily the original form of these churches. [Illustration: 694. View of West End of Abbey of Corvey.]