In many parts of Europe and beyond, the end of the First World War did not mean an end to the fighting.
The spread of radical political ideas inspired by the Russian Revolution led to a series of civil wars and clashes between communist and anti-communist forces. Several new nations were established after the war in the wake of the Russian Revolution and the collapse of the defeated empires. Where the territorial claims of these new nations overlapped, they fought to establish their borders.
Within the British Empire too, disaffected nations fought for independence.
Peace did not return to Europe until 1923, five years after the end of the First World War.
Russian Civil War 1917-1923
The Russian Revolutions of 1917 sparked a complex struggle between the Red Army of the Bolsheviks and the White Army, a union of Russian anti-communist forces.
In addition, groups of armed peasants known as Green Armies defended their communities from the plundering of both sides.
The White Army was supported by a number of foreign nations including the new republics that formed after the revolution, the Allied Powers and Germany.
Bitter fighting occurred on three fronts and atrocities were committed by both sides.
Despite some early successes, the White Army were eventually defeated. The Union of Soviet Socialist Republics was created in December 1922.
Finnish Civil War 1918
Finland was a Grand Duchy of the Russian Empire when the First World War broke out.
The Russian Revolution in 1917 left a power vacuum in Finland and a struggle ensued between the conservative Whites who wanted independence from Soviet Russia and the socialist Reds who opposed the separation.
The Whites, mainly from the rural north, were supported by Germany while the Reds, mainly from the industrial south, were supported by Russia.
Many thousands of Finns died in the fighting, prison camps and terror attacks.
By May 1918, the Whites had defeated the Reds. Finland became a republic in 1919.
German Revolution 1918-1919
Angry at being ordered to fight a desperate last battle against the British Navy, German sailors revolted in October 1918. The civil unrest spread throughout Germany as people blamed their leaders for Germany’s defeat and the suffering they had endured during the war.
The German Republic was proclaimed in November; the Kaiser abdicated and went into exile in the Netherlands.
Uprisings by radical communist groups such as the Spartacist League were suppressed by the army and the Freikorps, a pro-government paramilitary militia consisting mainly of former soldiers.
By late 1919, most opposition to the new German Republic had been defeated.
Estonian-Soviet 1918-1920
Estonia was part of the Russian Empire when the First World War began. It was occupied by Germany in the final year of the war.
Estonia became an independent state following the Russian Revolution and the defeat of Germany.
Soviet Russia attacked Estonia as part of their large westward offensive in November 1918, taking advantage of the withdrawal of German troops.
Estonia was supported by Latvia, Britain, White Russian forces and volunteers from Scandinavia.
This helped them to reverse the Russian advance from early 1919.
Eventually, in February 1920, Soviet Russia agreed to acknowledge Estonian independence.
Latvian-Soviet War 1918-1920
Like Estonia, Latvia gained independence from Russia shortly after the First World War. It too was quickly invaded by Soviet Russia.
Latvian and German troops were forced to retreat and the Soviets proclaimed the Latvian Socialist Soviet Republic in January 1919.
The Latvian army, supported by German and Estonian troops, counterattacked and retook most of their land by June.
Shortly afterwards, it became clear that the German troops were trying to dominate the region. Latvian and Estonian forces had to fight a series of battles against them until the Allies intervened.
Soviet Russia acknowledged Latvian independence in August 1920.
Polish-Soviet War 1919-1921
Poland re-established itself as an independent state at the end the First World War, encompassing parts of the former German, Austro-Hungarian and Russian empires.
The Polish-Soviet War began as a border dispute with Soviet Russia. Russia later saw the war as an opportunity to expand to the west, supporting communist movements in eastern and central Europe.
After some early successes, Poland suffered a series of defeats in 1920, retreating nearly as far as Warsaw. Here they stopped the Russian advance and won a decisive victory.
An armistice was agreed soon afterwards and a peace treaty was signed in March 1921.
Polish-Ukrainian War 1918-1919
Soon after the Austro-Hungarian empire collapsed in October 1918, the Ukrainian population, wanting independence, proclaimed the West Ukrainian People’s Republic.
Some of the territory that they claimed was also claimed by Poland and a border war began.
The fighting was centred on the West Ukrainian capital Lviv, which fell to the Poles in November 1918.
Ukrainian troops made several unsuccessful attempts to retake the city. By July 1919, with the help of Polish reinforcements from the Western Front, the Poles had defeated the Ukrainians, who lacked sufficient arms and ammunition.
The disputed West Ukrainian lands became part of Poland.
Polish–Lithuanian War 1920
Part of the Russian Empire before the First World War, Lithuania was occupied by Germany from 1915.
It became an independent state following the Russian Revolution and the defeat of Germany.
It first fought against Soviet Russia and this war ended in a peace treaty in July 1920.
Lithuania then took advantage of the Polish retreats during the Polish-Soviet War to seize the lands they had claimed in their treaty with Soviet Russia.
When the Poles advanced again, Lithuania defended its new borders against them.
The fighting was eventually stopped in November 1920 with the help of the League of Nations.
Greco-Turkish War 1919-1922
The Allies promised Greece that it would receive territory when the defeated Ottoman Empire was broken up after the First World War.
Greek forces duly landed in Smyrna (Izmir), in May 1919 and seized parts of Anatolia.
Turkish nationalists objected to the partitioning of Turkish lands and the presence of occupying forces; soon, their movement gained strength.
Nationalist forces stopped the Greek advance and drove them back to Smyrna, which they recaptured in September 1922.
Many civilians were killed and settlements destroyed by both sides during the conflict.
The boundaries of modern Turkey were established through victory in this conflict.
Egyptian Revolution 1919
Britain effectively ruled Egypt since British forces occupied the country in 1882.
When the First World War broke out, Britain declared Egypt to be a British protectorate.
Unhappy about the way they were treated by the British during the war, the Egyptians began pushing for independence as soon as the fighting ceased.
A series of demonstrations, strikes and uprisings occurred in 1919. During them, around 800 Egyptians were killed.
It soon became clear that the protectorate could not be made to work.
Britain declared Egyptian independence in February 1922 although the British presence in Egypt continued.
Irish War of Independence 1919-1921
Ireland became part of the United Kingdom at the beginning of the nineteenth century. The failed Easter Rising in 1916 and the strong British response to it increased sympathy for the independence movement.
Sinn Féin gained much support in the 1918 General Election and declared an Irish Republic the following year.
A guerrilla war ensued between the Irish Republican Army and British forces in which ambushes played a large part.
The result was the 1921 Anglo-Irish Treaty which confirmed the partitioning of Ireland, the south becoming an autonomous Dominion of the British Empire and the north remaining in the United Kingdom.
The treaty did not bring peace to Ireland but sparked a civil war between the pro-treaty Nationalists and the anti-treaty Republicans, which was eventually won by the Nationalists.