The Treaty of Lausanne is signed by the Allies and Turkey, the successor state to the Ottoman Empire. It supersedes the failed Treaty of Sèvres and offically ends the First World War.

The Treaty of Sèvres is signed by the Allies and the Ottoman Empire. The treaty is not recognised by the Turkish national movement, which considers the Constantinople (now Istanbul) government illegitimate.

The Treaty of Trianon is signed by the Allies and newly-independent Hungary.

The first meeting of the League of Nations is held in London.

The Treaty of Neuilly-sur-Seine is signed by the Allies and Bulgaria.

The Treaty of Saint-Germain-en-Laye is signed by the Allies and newly-independent Austria.

The Treaty of Versailles is signed by the Allies and Germany.

At the Paris Peace Conference a proposal to create the League of Nations, an open diplomatic forum, is accepted.

A peace conference opens in Paris to negotiate treaties between the Allies and the defeated Central Powers. Many view the terms of the treaties as excessively punitive.

Yugoslavia is formed by merging Serbia with several territories of the former Austro-Hungarian Empire.

Czechoslovakia is formed by merging several territories of the former Austro-Hungarian Empire.

The Ottoman Empire signs the Armistice of Mudros with the Allies.

Leon Trotsky signs a punitive peace treaty with Germany on behalf of Bolshevik Russia.

The Representation of the People Act 1918 is given Royal Assent, giving the vote to women over 30.

The Germans agree an armistice with Bolshevik Russia.

The Bolsheviks seize power in Russia during the October Revolution.

The Allies agree to establish a Supreme War Council at Versailles.

Romania enters the war on the Allied side, but is defeated within a few weeks.

Following the seizure of German ships in Lisbon, Germany declares war on Britain’s ally Portugal.

The Allies offer Italy territorial gains in any post-war settlement in return for their support.

The Ottomans close the Dardanelles Strait, a shipping route linking the Black Sea and the Mediterranean.

Britain declares war on Germany following the latter’s violation of the Treaty of London (1839), which guaranteed Belgian neutrality.

Germany declares war on France (an ally of Russia) and neutral Belgium. The Germans’ Schlieffen Plan is based on a quick strike against France while Russia is slowly mobilising.

Germany and the Ottoman Empire (now Turkey) sign a secret alliance treaty aimed against Russia.

Germany warns Russia to cease mobilisation despite the latter’s claim that this is only aimed against the Austro-Hungarians.

Austria-Hungary declares war on Serbia. Russia mobilises in support of its Serb ally.

Austria-Hungary sends Serbia an impossible ultimatum, which is rejected.

Germany assures Austria-Hungary of its support against Russia should the latter oppose Austria’s planned attack on Serbia.