Notwithstanding these triumphs, Russia's slow technical and economic development in the first half of the 19th century caused her to fall behind other world powers in the field of steamboat construction. It was in 1826 that the Russians built their first armed steamboat "Izhora". At the outbreak of the Crimean War in 1853, steamships were few and sailing ships heavily predominated. The Battle of Sinope, won by Pavel Nakhimov, is remembered in history as the last significant naval battle involving sailing ships. During the Siege of Sevastopol in 1854–1855, Russian sailors set an example of using all means possible for defending their base from land and sea. Although the Russians introduced modern naval mining in the Baltic and repelled the Siege of Petropavlovsk-Kamchatskiy in the Pacific, Sevastopol was finally surrendered on honourable terms but only after the Russians sank their ships to prevent outside use of the harbor. In accordance with the Treaty of Paris, Russia lost its right to have a military fleet in the Black Sea.