The Byzantine Empire generally refers to the later Eastern Roman Empire, or the last remnants of the Roman Empire at the bottom of its decline. In 1453, the Ottoman Turks successfully conquered the capital Constantinople and renamed it Istanbul – marking the end of the Byzantine and East Roman Empires.

Japan began to ramp up its imperial ambitions towards the beginning of the 20^th century. It won possession of Taiwan in the First Sino-Japanese War which was originally fought over Korea, and then later annexed Korea in 1910. The Sakhalin Island was a Russian possession that Japan laid claim to, and won a portion of during the Russo-Japanese war that was also fought over imperial ambitions over Korea. Russia would later win back its losses following the end of World War II.

Following Japan’s annexation of Korea in 1910, Japan controlled Korea until the end of World War II in 1945. Japan was then forced to relinquish its control of Korea to the Soviet Union and the United States, who partitioned the nation into the North (controlled by the Soviets) and the South (controlled by the Americans).

With America’s decisive victory over Japan through the reclamation of the Pacific and the use of two atomic weapons, Japan’s imperialistic ambitions came to a final end. Japan relinquished all of its claimed territories and agreed to strict demilitarizing under American watch.

France maintained a strong alliance with Russia because both of these Great Powers feared an expansion of German influence in Central and Eastern Europe. Germany was closely allied with Austria-Hungary, which had long-standing tensions with Russia, due to its domination of Slavic minorities. Similarly, the Ottoman Empire and Russia were often at odds. Great Britain was not governed by an absolutist regime; rather, it was a constitutional monarchy.

Although it is most strongly associated with WWI, trench warfare was used in wars long before, including during the American Civil War. During WWI various technologies were introduced in attempts to break through entrenched defenses, including poison gas (first used in 1915), flame-throwers (also 1915), and tanks (introduced in 1916). Zepplins were used in bombing raids against Allied cities, most particularly London, where several hundred civilians were killed by bombs.

The United States sent a military force of 5,000 men to Northern Russia and another 8,000 to Siberia in the summer of 1918. While the primary objective of these troops was to secure weapons stockpiles, there was also a desire on the part of the Allies to defeat the Bolshevik forces and bring Russia back into the war. Poland did not exist as a country until after WWI. Finland was invaded by the Soviet Union in 1939. Neither China nor Germany had the military strength to mount an invasion of Russia in the summer of 1918.

Europe was, of course, the scene of most of the fighting during the war, but there were also important military engagements in the Middle East, especially between the British and the Ottoman Empire. The Allies launched attacks against German colonies in Africa over the course of the war, and an important battle took place outside the Chinese city of Tsintao, which was controlled by Germany before the war. No military action took place in South America.

Adolf Hitler served in the Bavarian Army during World War I. He was wounded in battle, and gassed during one of the last Allied gas attacks of the war. Roosevelt served as the Secretary of the Navy during the war, while his future allied collaborator, Churchill, served as the First Lord of the Admiralty. Stalin was excused from military service due to the fact that his left arm was crippled by a childhood injury. As the Crown Prince of Japan, Hirohito had military rank, but was (of course) never allowed to fight.

The unification of Germany occurred just as European powers were beginning to create colonies in Africa; thus, Germany was able to gain control of South West Africa (Namibia) and German East Africa (Burundi, Rwanda, and Tanzania). Southeast Asia was dominated by France, Central Asia was largely controlled by Russia (with some British outposts, e.g. in Afghanistan), and the Middle East/West Asia was part of the Ottoman Empire (although Egypt was largely controlled by Britain). China remained an independent state, although the central government was greatly weakened by European and American influences.