world war

First world war 1:

Date :  28 July 1914 – 11 November 1918 (Armistice)
            Treaty of Versailles signed 28 June 1919
            Treaty of Saint-Germain-en-Laye signed 10 September 1919
            Treaty of Neuilly-sur-Seine signed 27 November 1919
            Treaty of Trianon signed 4 June 1920
            Treaty of Sèvres signed 10 August 1920
Location :

Europe, Africa, the Middle East, the Pacific Islands, China and off the coast of  South  Africa and North   America.
Result     Allied victory

    End of the German, Russian, Ottoman, and Austro-Hungarian empires
    Formation of new countries in Europe and the Middle East
    Transfer of German colonies and regions of the former Ottoman Empire to other powers
    Establishment of the League of Nations.

World War I (WWI) was a global war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918. It was predominantly called the World War or the Great War from its occurrence until the start of World War II in 1939, and the First World War or World War I thereafter. It involved all the world's great powers, which were assembled in two opposing alliances: the Allies (based on the Triple Entente of the United Kingdom, France and Russia) and the Central Powers (originally centred around the Triple Alliance of Germany, Austria-Hungary and Italy; but, as Austria–Hungary had taken the offensive against the agreement, Italy did not enter into the war). These alliances both reorganised (Italy fought for the Allies), and expanded as more nations entered the war. Ultimately more than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. More than 9 million combatants were killed, largely because of enormous increases in lethality of weapons, thanks to new technology, without corresponding improvements in protection or mobility. It was the sixth-deadliest conflict in world history, subsequently paving the way for various political changes such as revolutions in the nations involved.

Long-term causes of the war included the imperialistic foreign policies of the great powers of Europe, including the German Empire, the Austro-Hungarian Empire, the Ottoman Empire, the Russian Empire, the British Empire, the French Republic, and Italy. The assassination on 28 June 1914 of Archduke Franz Ferdinand of Austria, the heir to the throne of Austria-Hungary, by a Yugoslav nationalist in Sarajevo, Bosnia and Herzegovina was the proximate trigger of the war. It resulted in a Habsburg ultimatum against the Kingdom of Serbia. Several alliances formed over the previous decades were invoked, so within weeks the major powers were at war; via their colonies, the conflict soon spread around the world.

On 28 July, the conflict opened with the Austro-Hungarian invasion of Serbia, followed by the German invasion of Belgium, Luxembourg and France; and a Russian attack against Germany. After the German march on Paris was brought to a halt, the Western Front settled into a static battle of attrition with a trench line that changed little until 1917. In the East, the Russian army successfully fought against the Austro-Hungarian forces but was forced back from East Prussia and Poland by the German army. Additional fronts opened after the Ottoman Empire joined the war in 1914, Italy and Bulgaria in 1915 and Romania in 1916. The Russian Empire collapsed in March 1917, and Russia left the war after the October Revolution later that year. After a 1918 German offensive along the western front, the Allies drove back the German armies in a series of successful offensives and United States forces began entering the trenches. Germany, which had its own trouble with revolutionaries at this point, agreed to a cease-fire on 11 November 1918, later known as Armistice Day. The war had ended in victory for the Allies.

Events on the home fronts were as tumultuous as on the battle fronts, as the participants tried to mobilize their manpower and economic resources to fight a total war. By the end of the war, four major imperial powers — the German, Russian, Austro-Hungarian and Ottoman empires — ceased to exist. The successor states of the former two lost a great amount of territory, while the latter two were dismantled entirely. The map of central Europe was redrawn into several smaller states. The League of Nations was formed in the hope of preventing another such conflict. The European nationalism spawned by the war and the breakup of empires, the repercussions of Germany's defeat and problems with the Treaty of Versailles are agreed to be factors contributing to World War II.

World War II
Date     1 September 1939 – 2 September 1945 
             (6 years, 1 day)
Location     Europe,Pacific,Atlantic,South-East    Asia, China, Middle East, Mediterranean and Africa, briefly North America 
Result     Allied victory

    Dissolution of the Third Reich
    Creation of the United Nations
    Emergence of the United States and the Soviet Union as superpowers 

World War II, or the Second World War (often abbreviated as WWII or WW2), was a global war that was under way by 1939 and ended in 1945. It involved a vast majority of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis. It was the most widespread war in history, with more than 100 million people serving in military units. In a state of "total war", the major participants placed their entire economic, industrial, and scientific capabilities at the service of the war effort, erasing the distinction between civilian and military resources. Marked by significant events involving the mass death of civilians, including the Holocaust and the only use of nuclear weapons in warfare, it resulted in 50 million to over 70 million fatalities. These deaths make World War II the deadliest conflict in all of human history. Although the Empire of Japan was already at war with the Republic of China in 1937, the world war is generally said to have begun on 1 September 1939, with the invasion of Poland by Germany, and subsequent declarations of war on Germany by France and most of the countries of the British Empire and Commonwealth. Germany set out to establish a large empire in Europe. From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or subdued much of continental Europe; amid Nazi-Soviet agreements, the nominally neutral Soviet Union fully or partially invaded, occupied and annexed territories of its six European neighbours, including Poland. The United Kingdom and its Commonwealth remained the only major force continuing the fight against the Axis, with battles taking place in North Africa as well as the long-running Battle of the Atlantic. In June 1941, the European Axis launched an invasion of the Soviet Union, giving a start to the largest land theatre of war in history, which tied down the major part of the Axis' military forces. In December 1941, the Empire of Japan, which aimed to dominate the East Asia and Indochina, joined the Axis, attacked the United States and European territories in the Pacific Ocean, and quickly conquered much of the West Pacific. The Axis advance was stopped in 1942, after Japan lost a series of naval battles and European Axis troops were defeated in North Africa and, decisively, at Stalingrad. In 1943, with a series of German defeats in Eastern Europe, the Allied invasion of Fascist Italy, and American victories in the Pacific, the Axis lost the initiative and undertook strategic retreat on all fronts. In 1944, the Western Allies invaded France, while the Soviet Union regained all of its territorial losses and invaded Germany and its allies. The war in Europe ended with the capture of Berlin by Soviet and Polish troops and the subsequent German unconditional surrender on 8 May 1945. During 1944 and 1945 the United States defeated the Japanese Navy and captured key West Pacific islands, dropping atomic bombs on the country as the invasion of the Japanese Archipelago became imminent. The war in Asia ended on 15 August 1945 when the Empire of Japan agreed to surrender. The total victory of the Allies over the Axis in 1945 ended the conflict. World War II altered the political alignment and social structure of the world. The United Nations (UN) was established to foster international cooperation and prevent future conflicts. The great powers that were the victors of the war— the United States, Soviet Union, China, the United Kingdom, and France— became the permanent members of the United Nation's Security Council.[3] The Soviet Union and the United States emerged as rival superpowers, setting the stage for the Cold War, which lasted for the next 46 years. Meanwhile, the influence of European great powers started to decline, while the decolonisation of Asia and Africa began. Most countries whose industries had been damaged moved towards economic recovery. Political integration, especially in Europe, emerged as an effort to stabilise postwar relations.