After a series of fratricidal struggles, the Ottomans dealt with the problem of the succession by confining the sultan’s male relatives to the palace’s Inner Courtyard or harem, thereby preventing future sultans from acquiring vital knowledge of military and secular affairs. From the seventeenth century the Ottoman sultans, who came to power as a result of “Byzantine” maneuvers and harem intrigues, lacked experience in the field and familiarity with the realities of politics. The power of the state and the army held up briefly under ruthless viziers such as Mehmed Koprulu (r. 1656–61), son of an Albanian Christian, and his son Ahmed (r. 1661–76), allowing further expansion north of the Crimea and (after Ahmed’s death) even a second siege of Vienna (1683). The process of decline, however, proved irreversible. The influx of Spanish silver from the Americas created a massive inflation problem, undermining the commercial classes and the ability of government to pay for troops whose modern weaponry (muskets and gunpowder) required cash rather than booty. Provincial governors and local magnates gained power at the expense of the center, hiring private armies or raising taxes for themselves. The Janissaries, who had evolved into a privileged body within the state, became enmeshed in large-scale nepotism and misrule. Land concessions that should have nurtured agriculture degenerated into tax-farms, driving cultivators off the land, and creating gangs of rural bandits or urban migrants who drifted into cities already overcrowded and subject to famine, plague, and disorder. The millet system, which allowed the Christian and Jewish communities (and in Iraq the Shiite) a high degree of administrative autonomy, undermined the legitimacy of the state by privileging Western traders and encouraging Greek and Balkan Christians to look toward the Empire’s enemies in Russia and Western Europe for inspiration and support. Internally decentralized, the Empire proved no match for the rising powers of Europe, whose military and economic systems were beginning to benefit from the revolution in scientific thought. During the last two decades of the seventeenth century, the European powers made significant advances at the Empire’s expense. Between 1684 and 1687 the Habsburgs took most of Hungary north of the Danube and took Serbia in 1689. The Venetians seized Dalmatia and southern Greece (Morea). Poland invaded Podolia, and the Russians, under the newly modernized army of Peter the Great, took Azov in the Crimea. Although the Ottomans regained some of these territorial losses during the first half of the eighteenth century, in the longer term they were unable to stem the tide of Russian advance. In 1768 the Russians began a new campaign, occupying Moldavia and Wallachia (modern Romania) and the Crimea. Under the humiliating terms of the treaty of Kuchuk Kaynarca (1774) the Ottomans were obliged to allow Russia a foothold on the Black Sea, as well as freedom of navigation and commerce, with access to the Mediterranean and to overland trade in the Empire’s Asian and European provinces. Although Moldavia and Wallachia remained technically under Ottoman suzerainty, the increased autonomy they were granted laid them open to Russian manipulation. Under Russian pressure a clause permitting the erection of a Russian church in Istanbul would be converted into a general right of Russian intervention on behalf of all the sultan’s Orthodox Christian subjects.