What gave the Hebdomon its importance and explains its history was, primarily, its favourable situation for the establishment of a large military camp in the neighbourhood of the capital. An extensive plain, with abundance of water, and at a convenient distance from the city, furnished a magnificent camping-ground for the legions of New Rome. This, in view of the military associations of the throne, especially during the earlier period of the Empire, brought the emperors frequently to the suburb to attend great functions of State, and thus converted it also into an Imperial quarter, embellished with the palaces, churches, and monuments which spring up around a Court. To these political reasons for the prosperity of the suburb were added the natural attractions of the place—its pleasant climate, its wide prospect over the Sea of Marmora, and the excellent sport obtained in the surrounding country. It was on the plain of the Hebdomon that Theodosius the Great joined the army which he led against the usurper Eugenius in Italy.[1224] There, the Gothic troops which Arcadius recalled from the war with Alaric took up their quarters under the command of Gainas, and there that emperor, accompanied by his minister Rufinus, held the memorable review of those troops, in the course of which Rufinus was assassinated in the Imperial tribune.[1225] It was at the Hebdomon that Gainas gathered the soldiers with which he planned to seize the capital.[1226] There Vitalianus encamped with more than sixty thousand men to besiege Constantinople in the reign of Anastasius I.[1227] Thither Phocas[1228] and Leo the Armenian[1229] brought the armies that enabled them to win the crown. And there Avars, Saracens, Bulgarians, and, doubtless, other foes halted to gaze upon the walls and towers they hoped to scale, or from which they retired baffled and broken.[1230] The plain at the Hebdomon was used, also, for military exercises and athletic sports, and consequently appears under the name of the Campus Martius,[1231] as though to give it the prestige of the ground devoted to similar purposes on the banks of the Tiber. There recruits were drilled and trained in the use of arms,[1232] and there the popular game of polo was played.[1233]