The very prosperity of the country during the Roman occupation was one cause of its danger, presenting it as an alluring prize to the forces gradually arising along its frontiers. The extreme centralisation of the Byzantine system weakened, if it did not altogether exterminate, the power of local resistance and administration. So long as the central government remained powerful all was well, but the danger of the system was manifested by the ease with which the Arab forces in 668 passed through the land from end to end, pausing only before the walls of Constantinople. The hold of the Saracen power, however, was not firm, and the Roman system was possessed of great latent vitality which in the end was equal to the emergency, so that in a series of campaigns extending from 920 to 965, the Saracens were driven back from point to point, until first Tarsus[123] was recovered and then Antioch, which had for more than three hundred years been in their possession. [Illustration: PLATE XXIX BAALBEK: SCULPTURE AND TEMPLE RUINS OF ROMAN PERIOD] The Seljûk Turks, who next appeared on the scene, were a more formidable and resistless enemy. Having at one time been the servants of the Arab sultans, they had now become the masters, and in 1067 they entered Asia Minor, conquering Cilicia and Cappadocia. Four years later the Emperor Romanus Diogenes himself was their prisoner, and by 1081 the whole centre and east of the tableland was recognised as their realm. Adopting a policy of depopulation and devastation, in which the whole of Phrygia was laid waste, the Turks rapidly set up an almost impassable frontier between themselves and the Byzantine power which still held sway in the West. Notwithstanding spasmodic efforts of the old rulers to regain their dominion, the country gradually relapsed into Orientalism, and with the rise of the Osmanli Turks from 1289 the Empire of the West rapidly disintegrated. Under the Seljûk rule, a new aspect of decorative art and architecture appeared in Asia Minor, a phase much neglected yet most worthy, as Professor Ramsay has pointed out, of special study. Under certain of their lines a brilliant series of monuments arose, among which the Hans[124] or roadside rest-houses are specially noteworthy, contributing also as they did to public security and pacification. In addition to these, other public works like their bridges and fortifications, as well as their mosques and colleges with cloisters and sculptures, are all evidence of one of the brightest phases of Moslem art. Some of the beautiful monuments which are shown in our illustrations, like the sculptured portal of the old school (or _Midresseh_) at Nigdeh, and the ‘tomb of Havanda,’ at the same place,[125] with its delicate tracery and design, belong to the best phases of this memorable period.