In 1838, through a series of military threats and promises, Britain imposed on the Porte a Tariff Convention which in effect transformed the Ottoman Empire into a virtual free-trade zone. Deprived of tariff revenues, the Porte’s ability to protect its nascent industries was seriously handicapped. From this moment the export of British manufactured goods to Turkey rose steeply. There was an elevenfold increase by 1850, making it one of Britain’s most valuable export markets (surpassed only by the Hanseatic towns and the Netherlands). After the repeal of the protectionist Corn Laws in 1846, British imports of cereals from Turkey, chiefly from Moldavia and Wallachia, increased as well. The advent of ocean steamships, steam river-boats and railroads opened up the Danube for the first time as a busy commercial highway. The river’s trade was dominated by British merchant ships exporting grain to western Europe and importing manufactures from Britain. The British were in direct competition with the merchants of Odessa, Taganrog and other Black Sea ports, from which the grain of Russia’s breadbasket in the Ukraine and south Russia was exported to the West. The cereal export market was increasingly important to Russia as the value of its timber trade declined during the steam age. By the middle of the nineteenth century the Black Sea ports were handling one-third of all Russian exports. The Russians tried to give their traders an advantage over their British rivals through their control of the Danube delta after 1829 by subjecting foreign ships to time-consuming quarantine controls and even allowing the Danube to silt up and become once more unnavigable.
On the eastern side of the Black Sea the commercial interests of Britain were increasingly bound up with the port of Trebizond, in north-eastern Turkey, from which Greek and Armenian merchants imported large quantities of British manufactured goods for sale in the interior of Asia. The growing value of this trade to Britain, observed Karl Marx in the
The danger Russia posed to India was the