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). [Illustration: FIG. 7. Persepolis, Apadana of Xerxes. (From _Iranische Felsreliefs_, by kind permission of the authors.)]