But what, perhaps, makes the reign of Valens chiefly memorable in the history of the city is that in his time the citizens of Constantinople had their first experience of a usurpation of the throne, and of an attack upon their walls. The former event was brought about by a certain Procopius, a cousin of the Emperor Julian. Making the most of his relationship to the family of Constantine, he took advantage of the discontent which the administration of Valens had provoked, and having won the populace of the city and a body of troops by means of liberal donatives, seized the palace and installed himself as Emperor. A sharp war with Valens ensued, in which the usurper was at length captured and put to death, while his partizans, and even persons suspected of having favoured his cause, were put to the torture, and had their property confiscated. Thus Constantinople learned--not for the last time--the meaning of a reign of terror. A signal example also was made of Chalcedon (Kadi Keui), on the opposite Asiatic shore, because its inhabitants had sided with Procopius. The walls of the town were ruthlessly torn down, and it was with the material thus made available that the Aqueduct of Valens was built and that the Baths of Constantine were repaired. Yet more serious was the quarrel of Valens with the Goths, whom he had permitted to cross the Danube in their retreat before the Huns, and settle in the territory we know as Bulgaria. The officials entrusted with the control of the refugees, and with the duty of providing them with food, did their work with such stupidity and rapacity that the high-minded Goths flew to arms, and, at the close of a struggle extending for upwards of a year, inflicted in 378 an overwhelming defeat upon the imperial forces, outside the walls of Adrianople. The Emperor himself and two-thirds of his army lay dead upon the field. The Roman legions had not known such a disaster since they were defeated by Hannibal at Cannæ. Flushed with victory, the Goths marched upon Constantinople, assailed the walls, and nearly burst the gates open. The honours of the defence fell to the widow of Valens, the Empress Dominica, who, with the money found in the treasury, raised a body of troops among the citizens, arming them with what weapons could be found. A body of Arab soldiers, recently arrived in the city, also rendered valuable aid. Sallying forth, they closed with the Goths in a desperate struggle. Victory wavered between the two sets of barbarians; when, suddenly, a long-haired, almost naked Arab, uttering a loud, hoarse, and doleful cry, like a bird of evil omen, rushed upon the Goths, and drawing his dagger, cut the throat of an opponent, and then slaked his thirst at the flowing wound. What with the impression produced by this horrid incident, added to a growing sense of the impossibility of their taking a fortified place, the Goths gave up the contest and retired from the city. This was the first siege of Constantinople.