Beginning with Italy in 1927, several countries experimented with using parachutes to drop soldiers behind enemy lines. The regular Soviet Airborne Troops were established as early as 1931 after a number of experimental military mass jumps starting from August 2, 1930. Earlier the same year, the first Soviet mass jumps led to the development of the parachuting sport in the Soviet Union. By the time of World War II, large airborne forces were trained and used in surprise attacks, as in the battles for Fort Eben-Emael and The Hague, the first large-scale, opposed landings of paratroopers in military history, by the Germans. This was followed later in the war by airborne assaults on a larger scale, such as the Battle of Crete and Operation Market Garden, the latter being the largest airborne military operation ever. Aircraft crew were routinely equipped with parachutes for emergencies as well.