information:extraction, structural:summarization, structural:reformatting
Nineteenth century

Gaining control of, or guaranteed access to, the strait became a key foreign-policy goal of the Russian Empire during the 19th century. During the Napoleonic Wars, Russia—supported by Great Britain in the Dardanelles Operation — blockaded the straits in 1807.

In 1833, following the Ottoman Empire 's defeat in the Russo-Turkish War of 1828–1829, Russia pressured the Ottomans to sign the Treaty of Hunkiar Iskelesi —which required the closing of the straits to warships of non-Black Sea powers at Russia's request. That would have effectively given Russia a free hand in the Black Sea.

This treaty alarmed the Ottoman Empire, who were concerned that the consequences of potential Russian expansionism in the Black Sea and Mediterranean regions could conflict with their own possessions and economic interest in the region. At the London Straits Convention in July 1841, the United Kingdom, France, Austria, and Prussia pressured Russia to agree that only Turkish warships could traverse the Dardanelles in peacetime. The United Kingdom and France subsequently sent their fleets through the straits to defend the Danube front and to attack the Crimean Peninsula during the Crimean War of 1853–1856 – but they did so as allies of the Ottoman Empire. Following the defeat of Russia in the Crimean War, the Congress of Paris in 1856 formally reaffirmed the London Straits Convention.