As we should expect from geographical circumstances, Assyria's most perilous and persistent foreign enemies were the fierce hillmen of the north. In the east, storms were brewing behind the mountains, but they were not yet ready to burst. South and west lay either settled districts of old civilization not disposed to fight, or ranging grounds of nomads too widely scattered and too ill organized to threaten serious danger. But the north was in different case. The wild valleys, through which descend the left bank affluents of the Upper Tigris, have always sheltered fierce fighting clans, covetous of the winter pasturage and softer climate of the northern Mesopotamian downs, and it has been the anxious care of one Mesopotamian power after another, even to our own day, to devise measures for penning them back. Since the chief weakness of these tribes lies in a lack of unity which the subdivided nature of their country encourages, it must have caused no small concern to the Assyrians that, early in the ninth century, a Kingdom of Urartu or, as its own people called it, Khaldia, should begin to gain power over the communities about Lake Van and the heads of the valleys which run down to Assyrian territory. Both Ashurnatsirpal and Shalmaneser led raid after raid into the northern mountains in the hope of weakening the tribes from whose adhesion that Vannic Kingdom might derive strength. Both kings marched more than once up to the neighbourhood of the Urmia Lake, and Shalmaneser struck at the heart of Urartu itself three or four times; but with inconclusive success. The Vannic state continued to flourish and its kings--whose names are more European in sound than Asiatic--Lutipris, Sarduris, Menuas, Argistis, Rusas--built themselves strong fortresses which stand to this day about Lake Van, and borrowed a script from their southern foes to engrave rocks with records of successful wars. One of these inscriptions occurs as far west as the left bank of Euphrates over against Malatia. By 800 B.C., in spite of efforts made by Shalmaneser's sons to continue their father's policy of pushing the war into the enemy's country, the Vannic king had succeeded in replacing Assyrian influence by the law of Khaldia in the uppermost basin of the Tigris and in higher Mesopotamia--the "Nairi" lands of Assyrian scribes; and his successors would raid farther and farther into the plains during the coming age. SECTION 3. THE MEDES