But if we have little knowledge of the Lakhmid ḥîrahs which were the precursors of Ukhaiḍir on the eastern frontiers of the desert, we have another and a richer source of information in the Sasanian palaces. The Lakhmid princes stood in close relations with the Sasanian empire. Among the officials of the Persian court there was an Arab secretary whose special duty it was to conduct the correspondence with ‘the land of the Arabs’. Moreover, it is related that the Arab phylarch paid a yearly visit to the court of the Chosroës.[74] To a Lakhmid the education of a Persian prince was entrusted, and Lakhmid armies placed Bahrâm V upon a contested throne. The Christians of Ḥîrah belonged to the Nestorian church, the church of Assyria; we hear of one, the poet ‘Adi ibn Zaid, who was Arab secretary and enjoyed great influence with Khusrau Parwêz. Half allies, half vassals, the Lakhmid phylarchs fought side by side with the Persians against Rome;[75] they were sufficiently independent to receive an embassy from the Byzantine emperor, and sufficiently important to warrant an attempt on his part to buy them over from the Sasanians. Finally, at the beginning of the seventh century, Khusrau Parwêz set the Lakhmid dynasty aside and established in place of Nu’mân III an Arab of the Ṭayy, who lived and held his court at ‘Ain al-Tamr near Ukhaiḍir. Possibly the huge walls of Qaṣr Sham’ûn, on the outskirts of the oasis,[76] may date from the time when ‘Ain al-Tamr was the residence of the phylarch. But he was no longer an independent ruler; a Persian adviser was appointed to assist him, and a few years later the state was converted into a province of the Sasanian empire under a Persian regent. Independent or subject, the civilization of Ḥîrah must have been modelled upon that of Ctesiphon; Persian influence must have been predominant in its arts and its architecture, and the Lakhmid ḥîrahs must have reflected the glories of Sasanian palaces. It is to these palaces that we should look first for an explanation of the architectural scheme of Ukhaiḍir. One reservation must, however, be made. It is true that Ukhaiḍir cannot be regarded as primarily a fortress. The absence of any sufficient provision of water would have been a fatal weakness in time of siege. No cistern exists within the palace; no ancient well has been found, and if the conditions were the same of old as they are now (which is, however, by no means a safe assumption), any water within the palace would have been too brackish to drink, as is the case in the modern well in the palace yard. Moreover, the outer ring of walls, which encloses the northern annex, was obviously too weak for defence; it is more like the garden wall of a pleasure-ground. Nevertheless, considerable care has been lavished upon the defences of the main building. They were, and they are to this day, adequate for the spasmodic warfare of the Arab tribes. In the very act of construction the architect seems to have bethought him that such protection was necessary and to have added a strong girdle to his palace plan. On the other hand, the Sasanian palaces, so far as they are known to us, are either unfortified, or they stand within a fortified park, the walls and towers of which are not in direct structural relation with the residential buildings. At the same time Sasanian military works, where they have been examined, do not differ materially from those of Ukhaiḍir; the fortress of Qala’-i-Khusrau at Qaṣr-i-Shîrîn is an excellent case in point ([Plate 73], Fig. 1). It is a rectangular enclosure, about the size of Ukhaiḍir (roughly 180 metres square), surrounded by a wall which is strengthened by rounded towers. The towers are somewhat differently disposed from those of Ukhaiḍir; they are larger and they are set twice as far apart, but the scheme is the same in both places. The interior buildings are much ruined. A row of chambers, or more probably, from the width of the ruin heaps, a row of small courts with chambers grouped round them, adjoined the inner side of the walls, leaving a central court which was partly filled by a large building, rectangular in plan. The town wall of Dastadjird was also furnished with rounded towers.[77]

Almost without exception the plan of the Sasanian palaces is a development of the lîwân type, the origin of which is to be sought in the southern Hittite sphere, northern Syria and the mountain lands north of the Mesopotamian plain. The architecture of this region is known to us best through the excavations at Zindjirli, where the evolution of the southern Hittite palace can be traced over a period of close upon a thousand years.[78] It is an evolution which is dominated

Fig. 5. Zindjirli. (From Ausgrabungen in Sendschirli, by kind permission of the D. Orient-Gesellschaft.)

from the first to last by the monumental gateway. At Zindjirli the type appears in its earliest and simplest form in the gateways of the inner city wall, which Professor Koldewey places approximately in the thirteenth century before our era.[79] A doorway set back between a pair of solid towers leads into a narrow

Fig. 6. Pasargadae. (From Iranische Felsreliefs, by kind permission of the authors.)

court, placed latitudinally, with a second doorway opposite to the first ([Fig. 5], D). Three hundred years later this structure is adapted, in the earliest khilâni palace, to residential purposes ([Fig. 5], G).[80] The solid towers remain, but the space between them has been converted into a covered portico, or lîwân, and the inner latitudinal court has become a latitudinal hall with a small chamber at either end. The further development is characterized by the multiplication of chambers and the disappearance of features proper to the fortress. In the khilâni palace erected after Asarhaddon’s destruction of the city in the first half of the seventh century (it appears in Fig. 5 to the north-west of G), the arrangement of the subsidiary chambers is conceived on freer lines, the walls are thinner, the flanking towers of the lîwân have disappeared, and in their stead are set tower chambers; in short the fortress towers have given place to a purely decorative motive, the towered façade, which was destined to have a long and honourable history in Christian architecture.[81] That the Hittite khilâni was imitated by the Assyrians during the eighth and the seventh centuries we know both from inscriptions and from excavations.[82] To it the Assyrian builders owed the introduction of the column, which was foreign to their architecture. At Pasargadae the khilâni reappears in a form which bears testimony to its Hittite parentage.[83] The façade towers, the columned lîwân, the orthostatic construction, and more significant still, the latitudinal disposition of the chambers, are all to be found in the Pasargadae palaces, but the greater depth which was given to the principal room necessitated the introduction of a double line of columns to support the roof ([Fig. 6]). At Persepolis and at Susa the same scheme is carried out in colossal dimensions. It is found alike in the gigantic apadanas and in the palaces, in the one case adapted to the ceremonial magnificence of the Persian king of kings, in the other to the requirements of the dwelling-house. In the apadana, the lîwân was deepened and a second row of columns was added to the first; the hall of audience was magnified into a huge quadrangular chamber, the roof of which was supported by a forest of columns; solid towers of unburnt brick flanked the lîwân, and subsidiary lîwâns occupied the space behind them on either side of the audience hall ([Fig. 7]). In the palaces the towers were hollowed out into rooms correspondingly in depth with the lîwân, and the audience hall was flanked by side chambers. Where space permitted, as in the palace of Darius at Persepolis, additional rooms were disposed round a courtyard at the back of the edifice. So constituted, the Achaemenid palace reproduced the traits of the later khilânis at Zindjirli in a form adapted to new requirements ([Fig. 8]).