Orlov served in the Imperial Russian Army, and through his connections with his brother, became one of the key conspirators in the plot to overthrow Tsar Peter III and replace him on the Russian throne with his wife, Catherine. The plot, carried out in 1762, was successful, and Peter was imprisoned under Alexei Orlov's guard. He died shortly afterwards under mysterious circumstances, and it was popularly believed Orlov had either ordered, or personally carried out, his murder. Handsomely rewarded by Catherine after her accession, the Orlovs became powerful at court. Alexei was promoted and took part in the Russo-Turkish War of 1768–74, commanding a naval expedition to the Mediterranean in 1770, which destroyed the Ottoman fleet at the Battle of Chesma. For his success he was granted the honorific Chesmensky. The Russian victory sparked off the Orlov Revolt in the Greek territories of the Ottoman Empire soon afterwards.