As the building was begun in the year 437 B.C., and was entirely completed within a period of five years, and was one of the most imposing structures of its day, Pausanias is led to reflect that, “in felicity of execution and in boldness and originality of design, it rivalled the Parthenon.” Lübke’s comment on the structure is: “Thus in this building the idea of fortress-like defence, as well as festive welcome, was equally expressed. Especially admirable, however, was the rich ceiling of the great three-naved court, both on account of the bold span of its beams and the magnificent decoration of the spaces between them (the coffers), which were brilliant with gold and colors.[3] The Ionic form of the columns in the interior also corresponded with this festive, cheerful character; while the two rows of columns on the outside, together with the rest of the exterior of the building, exhibited the seriousness and dignity of the Doric style.” Thus has much been quoted in description and eulogy of this noble piece of architecture; would that as much might be quoted in respect to the talents and career of its gifted designer, but of him there is only the shadow of comment, from which it is possible to weave but the faintest fabric of certainty concerning his life. His name was Mnesicles, and we are told that he was a slave born in the household of Pericles. That he should have been chosen to create so important an architectural work speaks for the privilege which the humblest born might hope to attain in rising to positions of trust and prominence in the days of that great leader. Mnesicles early manifested an aptitude for architecture, and was permitted by his illustrious patron and owner to exercise his talent in the erection of buildings of inferior consequence before being entrusted with more ambitious works. The Propylæa was not the only work of magnitude upon which he was engaged, nor was it the most beautiful, in the judgment of some critics, although the most important, for he was the architect as well of the graceful Doric temple of Theseus, which has always been regarded as one of the finest architectural conceptions the ancient city of Athens possessed. [Illustration: THE FALL OF MNESICLES FROM THE PROPYLÆA.]