The War of the Polish Succession again called him into the field. In 1733, Lacy and Munnich expelled the Polish king, Stanisław I, from Warsaw to Danzig, which was besieged by them in 1734. Thereupon the Irishman was commanded to march towards the Rhine and join his 13,500-strong contingent with the forces of Eugene of Savoy. To that end his corps advanced into Germany and, meeting the Austrians on 16 August, returned to winter quarters in Moravia with exemplary discipline. Lacy had reached the rank of Field Marshal with the outbreak of the Russo-Turkish War, in which his success exceeded even the most unreasonable expectations. In 1736 he was in charge of the Don Army which took the key citadel of Azov, and in the next year his corps crossed the Syvash marshes into Crimea, where he fell upon the 15,000-strong Crimean army and routed them in two battles, on 12 and 14 June. In 1738, Lacy's corps again landed in Crimea and took the fortress of Çufut Qale near the Khan's capital, Bakhchisaray. As soon as peace had been restored, Lacy was reinstated as the Governor of Livland, while Emperor Charles VI conferred on him the title of imperial count. His indifference to politics prevented his downfall following Anna's death, when other foreign commanders fell into disgrace and were expelled from active service.
Question: What year did Lacy's corp cross the Syvash marshes into Crimea?
Answer: 1737