The early palaces of the Sassanians have ceased to exist.  Artaxerxes, the son of Babek, Sapor the first, and their immediate successors, undoubtedly erected residences for themselves exceeding in size and richness the buildings which had contented the Parthians, as well as those in which their own ancestors, the tributary kings of Persia under Parthia, had passed their lives.  But these residences have almost wholly disappeared.  The most ancient of the Sassanian buildings which admit of being measured and described are assigned to the century between A.D. 350 and 450; and we are thus unable to trace the exact steps by which the Sassanian style was gradually elaborated.  We come upon it when it is beyond the stage of infancy, when it has acquired a marked and decided character, when it no longer hesitates or falters, but knows what it wants, and goes straight to its ends.  Its main features are simple, and are uniform from first to last, the later buildings being merely enlargements of the earlier, by an addition to the number or to the size of the apartments.  The principal peculiarities of the style are, first, that the plan of the entire building is an oblong square, without adjuncts or projections; secondly, that the main entrance is into a lofty vaulted porch or hall by an archway of the entire width of the apartment; thirdly, that beside these oblong halls, the building contains square apartments, vaulted with domes, which are circular at their base, and elliptical in their section, and which rest on pendentives of an unusual character; fourthly, that the apartments are numerous and en suite, opening one into another, without the intervention of passages; and fifthly, that the palace comprises, as a matter of course, a court, placed towards the rear of the building, with apartments opening into it.

The oblong square is variously proportioned.  The depth may be a little more than the breadth, or it may be nearly twice as much.  In either case, the front occupies one of the shorter sides, or ends of the edifice.  The outer wall is sometimes pierced by one entrance only; but, more commonly, entrances are multiplied beyond the limit commonly observed in modern buildings.  The great entrance is in the exact centre of the front.  This entrance, as already noticed, is commonly by a lofty arch which (if we set aside the domes) is of almost the full height of the building, and constitutes one of its most striking, and to Europeans most extraordinary, features.  From the outer air, we look; as it were, straight into the heart of the edifice, in one instance to the depth of 115 feet, a distance equal to the length of Henry VII.’s Chapel at Westminster.  The effect is very strange when first seen by the inexperienced traveller; but similar entrances are common in the mosques of Armenia and Persia, and in the palaces of the latter country.  In the mosques “lofty and deeply-recessed portals,” “unrivalled for grandeur and appropriateness,” are rather