These were the two powers which from north and south watched with impatience the decay of Assyria. That they made no attempt upon her between 625 and 608 was probably due to several causes: their jealousy of each other, the Medes’ trouble with the Scythians, Nabopolassar’s genius for waiting till his forces were ready, and above all the still considerable vigour of the Assyrian himself. The Lion, though old,[38] was not broken. His power may have relaxed in the distant provinces of his empire, though, if Budde be right about the date of Habakkuk,[39] the peoples of Syria still groaned under the thought of it; but his own land—his _lair_, as the prophets call it—was still terrible. It is true that, as Nahum perceives, the capital was no longer native and patriotic as it had been; the trade fostered by Assurbanipal had filled Niniveh with a vast and mercenary population, ready to break and disperse at the first breach in her walls. Yet Assyria proper was covered with fortresses, and the tradition had long fastened upon the peoples that Niniveh was impregnable. Hence the tension of those years. The peoples of Western Asia looked eagerly for their revenge; but the two powers which alone could accomplish this stood waiting—afraid of each other perhaps, but more afraid of the object of their common ambition. It is said that Kyaxares and Nabopolassar at last came to an agreement;[40] but more probably the crisis was hastened by the appearance of another claimant for the coveted spoil. In 608 Pharaoh Necho _went up against the king of Assyria towards the river Euphrates_.[41] This Egyptian advance may have forced the hand of Kyaxares, who appears to have begun his investment of Niniveh a little after Necho defeated Josiah at Megiddo.[42] The siege is said to have lasted two years. Whether this included the delays necessary for the reduction of fortresses upon the great roads of approach to the Assyrian capital we do not know; but Niniveh’s own position, fortifications and resources may well account for the whole of the time. Colonel Billerbeck, a military expert, has suggested[43] that the Medes found it possible to invest the city only upon the northern and eastern sides. Down the west flows the Tigris, and across this the besieged may have been able to bring in supplies and reinforcements from the fertile country beyond. Herodotus affirms that the Medes effected the capture of Niniveh by themselves,[44] and for this some recent evidence has been found,[45] so that another tradition that the Chaldeans were also actively engaged,[46] which has nothing to support it, may be regarded as false. Nabopolassar may still have been in name an Assyrian viceroy; yet, as Colonel Billerbeck points out, he had it in his power to make Kyaxares’ victory possible by holding the southern roads to Niniveh, detaching other viceroys of her provinces and so shutting her up to her own resources. But among other reasons