The weakest point in the empire when Justinian took it over was its financial system. The cardinal maxim of political economy, that “taxes should be raised in the manner least oppressive to those who pay them” was as yet undreamt of. The exaction of arbitrary customs dues, and the frequent grant of monopolies was noxious to trade. The deplorable system of tax-farming through middlemen was employed in many branches of the revenue. Landed proprietors, small and great, were still mercilessly overtaxed, in consideration of their exemption from military service. The budget was always handicapped by the necessity for providing free corn for the populace of Constantinople. Yet in spite of all these drawbacks Justinian enjoyed an enormous and steady revenue. His finance minister, John of Cappadocia, was such an ingenious extortioner that the treasury was never empty in the hardest stress of war and famine: but it was kept full at the expense of the future. The grinding taxation of Justinian’s reign bore fruit in the permanent impoverishment of the provinces: his successors were never able to raise such a revenue again. Here again Justinian may well be compared to Louis XIV. Justinian’s policy divides into the departments of internal and foreign affairs. Of his doings as legislator, administrator, theologian, and builder, we shall speak in their proper place. But the history of his foreign policy forms the main interest of his reign. He had determined to take up a task which none of his predecessors since the division of the Empire under Arcadius and Honorius had dared to contemplate. It was his dream to re-unite under his sceptre the German kingdoms in the Western Mediterranean which had been formed out of the broken fragments of the realm of Honorius; and to end the solemn pretence by which he was nominally acknowledged as Emperor West of the Adriatic, while really all power was in the hands of the German rulers who posed as his vicegerents. He aimed at reconquering Italy, Africa, and Spain—if not the further provinces of the old empire. We shall see that he went far towards accomplishing his intention. But during the first five years of his reign his attention was distracted by other matters. The first of them was an obstinate war of four years’ duration, with Kobad, King of Persia. The causes of quarrel were ultimately the rival pretensions of the Roman and Persian Empires to the suzerainty of the small states on their northern frontiers near the Black Sea, the kingdoms of Lazica and Iberia, and more proximately the strengthening of the fortresses on the Mesopotamian border by Justinian. His fortification of Dara, close to the Persian frontier town of Nisibis, was the _casus belli_ chosen by Kobad, who declared war in 528, a year after Justinian’s accession.