Korea (1592–1598). The development in combined operations reached a new level during the Crusades, when the element of political alliance was introduced as an influence on the military strategy, for example in the Sixth Crusade. Although all combined operations until the invention of the combustion engine were largely dependent on the sailing vessels, it was with the creation of sophisticated rigging systems of the European Renaissance that the Age of Sail allowed a significant expansion in the scale of combined operations, notably by the European colonial empires. Some have argued that this was the first revolution in military affairs that changed national strategies, operational methods and tactics both at sea and on the land. One notable example of this evolution was the French Invasion of Egypt (1798). Modern history Though a significantly expanded combined operation, the Crimean War was the first example of a planned combined operations campaign that was directed as part of a multinational coalition strategy. Aside from being the first modern expeditionary operation that used steam powered warships and telegraph communications—which made it the departing point for the rest of the 19th and 20th century developments—it was also the first used as a military theatre instrument to force decision in the conflict. The next development in the evolution of combined operations was made during the expansion of the European Empires and the era of colonialism that also led to the inclusion of the combined operations methods into the direct expression of national strategies to avoid full-scale conflicts in the shape of the gunboat diplomacy approach. It was at this time that naval troops previously used almost exclusively for defence of vessels or minor beach operations were expanded to enable extended littoral operations. The colonial experience, though largely confined to the period before World War I, persisted well into the 20th century. The period of World War I that prolonged well past its completion into the 1920s saw combined operations established as a systematic and planned operations with larger scope then simple transportations of troops, and the beginnings of development in true combined operations at strategic, operational and tactical levels with the unsuccessful amphibious landing at Gallipoli. Not only did this operation combine the elements of overall war planning context, multinational deployment of forces as part of the same operation, and use of troops prepared for the landings (as opposed to disembarkation), as well as naval gunfire support