Russia and Sweden went to war, and the Ottomans got involved by retaking Azov and then making peace. Austria, Russia, Venice, and the Ottomans would go to war several times. By 1739, the Ottomans had actually retaken the Morea and Serbia. In the 1740s and the 1750s, the Ottomans began to modernize their military, but in the 1760s, the Ottomans went to war with Russia again. Russia took over Crimea in 1783 and claimed that Orthodox Christians living in the Ottoman Empire were under Russian protection. Selim III continued modernising the military, but the elite Janissary corps troops revolted. Napoleon attacked Egypt but was repulsed by the British.