It was the first completed of the extant buildings of the group of the Acropolis and dates from 466 B.C. [Footnote 11: See Appendix, p. 427.] [Illustration: FIG. 37.--PROPYLÆA AT ATHENS. PLAN.] In the +Propylæa+ (Fig. 37), the monumental gateway to the Acropolis, the Doric and Ionic orders appear to have been combined for the first time (437 to 432 B.C.). It was the master work of Mnesicles. The front and rear façades were Doric hexastyles; adjoining the front porch were two projecting lateral wings employing a smaller Doric order. The central passageway led between two rows of Ionic columns to the rear porch, entered by five doorways and crowned, like the front, with a pediment. The whole was executed with the same splendor and perfection as the other buildings of the Acropolis, and was a worthy gateway to the group of noble monuments which crowned that citadel of the Attic capital. The two orders were also combined in the temple of +Apollo Epicurius+ at +Phigalæa+ (Bassæ). This temple was erected in 430 B.C. by Ictinus, who used the Ionic order internally to decorate a row of projecting piers instead of free-standing columns in the naos, in which there was also a single Corinthian column of rather archaic design, which may have been used as a support for a statue or votive offering. +ALEXANDRIAN AGE.+ A period of reaction followed the splendid architectural activity of the Periclean age. A succession of disastrous wars--the Sicilian, Peloponnesian, and Corinthian--drained the energies and destroyed the peace of European Greece for seventy-five years, robbing Athens of her supremacy and inflicting wounds from which she never recovered. In the latter part of the fourth century, however, the triumph of the Macedonian empire over all the Mediterranean lands inaugurated a new era of architectural magnificence, especially in Asia Minor. The keynote of the art of this time was splendor, as that of the preceding age was artistic perfection. The Corinthian order came into use, as though the Ionic were not rich enough for the sumptuous taste of the time, and capitals and bases of novel and elaborate design embellished the Ionic temples of Asia Minor. In the temple of +Apollo Didymæus+ at Miletus, the plinths of the bases were made octagonal and panelled with rich scroll-carvings; and the piers which buttressed the interior faces of the cella-walls were given capitals of singular but elegant form, midway between the Ionic and Corinthian types. This temple belongs to the list of colossal edifices already referred to; its dimensions were 366 by 163 feet, making it the largest of them all. The famous +Artemisium+ (temple of Artemis or Diana) measured 342 by 163 feet. Several of the columns of the latter were enriched with sculptured figures encircling the lower drums of the colossal shafts. The most lavish expenditure was bestowed upon small structures, shrines, and sarcophagi. The graceful monument still visible in Athens, erected by