From the armistice of 1918 and the occupation of Anatolia to Sakarya, the Great Offensive and the Treaty of Lausanne — how the Ottoman defeat gave way to a new state.
Last reviewed on 27 September 2026.
The Turkish War of Independence — Kurtuluş Savaşı or İstiklal Harbi in Turkish — was the series of military and political struggles fought between 1919 and 1923 after the defeat of the Ottoman Empire in the First World War. It was waged on several fronts at once, against Greek, Armenian, French and, less directly, British and Italian forces, and it was also a contest for authority inside the country between the sultan's government in Istanbul and a nationalist movement based in Anatolia. Its outcome was the replacement of the punitive Treaty of Sèvres by the Treaty of Lausanne, the end of the Ottoman dynasty and, in October 1923, the proclamation of the Republic of Türkiye. This page sets out the main stages in order; each has a large and sometimes contested literature of its own.
The Ottoman Empire signed the Armistice of Mudros with the Allies on 30 October 1918. Its terms were severe: demobilisation of the army, Allied control of the Straits, and a clause (Article 7) allowing the Allies to occupy any strategic point if their security was threatened. In the following months British, French and Italian troops moved into parts of Anatolia and Thrace, an Allied fleet anchored off Istanbul, and the capital came under effective Allied supervision. France occupied Cilicia in the south, Italy landed in the Antalya region, and Britain held key points along the railways and the Straits.
The decisive shock came on 15 May 1919, when Greek troops landed at İzmir (Smyrna) with Allied approval, backed by the Greek government's aim of uniting areas with large Orthodox Greek populations to Greece. The landing was accompanied by violence against Muslim civilians and prisoners, and it galvanised resistance: local defence societies and irregular bands (Kuva-yi Milliye, the "national forces") began to form in western Anatolia. In the east, a new Armenian republic in the Caucasus claimed territory in the provinces of eastern Anatolia.
On 19 May 1919 Mustafa Kemal Pasha, a general who had made his name at Gallipoli, landed at Samsun on the Black Sea coast. He had been sent by the Istanbul government as an army inspector, officially to restore order and oversee demobilisation. Instead he set about organising resistance. The Amasya Circular of June 1919 declared that the nation's independence was in danger, that the Istanbul government could not fulfil its responsibilities, and that the nation's own will and determination would save it.
Two congresses then gave the movement a political structure. The Erzurum Congress (July–August 1919) brought together delegates from the eastern provinces, and the Sivas Congress (September 1919) extended the organisation to the whole country, uniting local defence societies under a single "Association for the Defence of the Rights of Anatolia and Rumelia" and electing a Representative Committee chaired by Mustafa Kemal. Both congresses rejected any mandate or partition and insisted on the territorial integrity of the Muslim-majority lands remaining after the armistice.
Those principles were written into the Misak-ı Milli, the National Pact, adopted by the last Ottoman parliament in Istanbul in January 1920. The Allies responded by formally occupying Istanbul on 16 March 1920, arresting nationalist deputies and deporting a number of them to Malta. Many who escaped made their way to Ankara, which Mustafa Kemal had chosen as the movement's headquarters.
On 23 April 1920 the Grand National Assembly of Türkiye opened in Ankara. It claimed to represent the will of the nation and assumed legislative and executive authority, with Mustafa Kemal as its president. The sultan's government regarded it as a rebellion; a religious ruling was issued against the nationalists, and Istanbul sponsored armed forces to suppress them. Through 1920 the Ankara government fought on two levels — against internal revolts, some encouraged by Istanbul and some driven by local grievances, and against the occupying powers. In January 1921 the Assembly adopted the Law on Fundamental Organisation, a short constitution declaring that sovereignty belonged unconditionally to the nation.
Against the Armenian republic, 1920. Forces under Kazım Karabekir took Kars; the war ended with the Treaty of Alexandropol in December 1920, and the frontier was settled by treaties with the Soviet republics in 1921.
Against French forces in Cilicia and around Maraş, Antep and Urfa, 1919–1921, with prolonged urban resistance. It ended with the Ankara Agreement with France in October 1921.
Against the Greek army in western Anatolia, 1919–1922. The main theatre of the war, it culminated at Sakarya in 1921 and in the Great Offensive of August 1922.
The eastern campaign of autumn 1920 was short and decisive. The Treaty of Alexandropol (Gümrü) ended the fighting; Armenia soon came under Soviet rule, and the border was confirmed by the treaties of Moscow (March 1921) and Kars (October 1921). The rapprochement also brought the nationalists Soviet money and arms at a critical time.
In the south, the French occupation of Cilicia met resistance from local forces in Maraş, Urfa and Antep, the last of which endured a long siege; the city later received the honorific "Gazi", hence Gaziantep. France, weighing the cost of the campaign, negotiated directly with Ankara, and the Ankara Agreement of October 1921 ended hostilities and effectively recognised the nationalist government. Italy, too, withdrew its forces from southern Anatolia during 1921. These arrangements freed troops for the west and split the Allied front.
The Greek army advanced inland from İzmir from 1920. The nationalists, having replaced irregular forces with a regular army under İsmet Pasha, checked the advance at the First and Second Battles of İnönü in January and March–April 1921. But in the summer of 1921 a larger Greek offensive won the battles around Kütahya and Eskişehir, and the Turkish army fell back east of the Sakarya river, less than a hundred kilometres from Ankara. The Assembly appointed Mustafa Kemal commander-in-chief with extraordinary powers, and the country was mobilised through requisition orders on food, animals, cloth and transport.
The Battle of Sakarya, fought over roughly three weeks from late August to mid-September 1921, was one of the longest pitched battles of the war. The Greek army was unable to break through and withdrew to a line near Eskişehir and Afyon. Sakarya is usually regarded as the turning point: the Assembly conferred the title of Gazi and the rank of marshal on Mustafa Kemal, and diplomatic recognition of Ankara began to follow.
After almost a year of preparation, the Turkish army launched the Great Offensive (Büyük Taarruz) on 26 August 1922 against the Greek positions near Afyonkarahisar. The Greek front collapsed within days, and on 30 August the main Greek force was defeated in the Battle of Dumlupınar, also called the Commander-in-Chief's Battle. The date is still celebrated as Victory Day. Turkish forces reached İzmir on 9 September 1922. A great fire followed in the days after, destroying the Greek and Armenian quarters of the city; responsibility for it remains disputed between Turkish and Greek historiography, while the scale of the destruction and the human suffering of the refugees crowding the waterfront are not. The retreating Greek army and advancing Turkish forces were both responsible for serious atrocities against civilians during the campaign.
With nationalist forces approaching the Straits, a confrontation with British troops at Çanakkale (the Chanak Crisis) briefly threatened a new war. It was defused by the Armistice of Mudanya, signed on 11 October 1922, under which Greece withdrew from eastern Thrace and the Allies accepted that Istanbul and the Straits would pass to the Ankara government once a peace treaty was agreed.
The Allies invited both the Istanbul and the Ankara governments to the peace conference. The Assembly responded on 1 November 1922 by abolishing the Ottoman sultanate, separating it from the caliphate. The last sultan, Mehmed VI Vahdettin, left Istanbul on a British warship later that month, and his cousin Abdülmecid was chosen as caliph without political power; the caliphate itself was abolished in March 1924.
The conference at Lausanne opened in November 1922, with İsmet Pasha leading the Turkish delegation. After a break in the talks and hard bargaining over the Straits, the capitulations, Ottoman debt and the status of Mosul, the Treaty of Lausanne was signed on 24 July 1923. It recognised Turkish sovereignty over essentially the borders of today's Türkiye (with Mosul left to later negotiation and the Hatay question arising later), abolished the capitulations that had given foreigners legal and economic privileges, and set out protections for non-Muslim minorities. Allied forces left Istanbul, and Turkish troops entered the city on 6 October 1923. Ankara became the seat of government on 13 October, and the Republic was proclaimed on 29 October 1923.
A separate convention signed at Lausanne in January 1923 provided for a compulsory exchange of populations between Greece and Türkiye, defined by religion rather than language. Orthodox Christians of Turkish nationality were to go to Greece and Muslims of Greek nationality to Türkiye, with exceptions for the Greek Orthodox of Istanbul and the Muslims of western Thrace. Most of the Anatolian Orthodox population had already fled or been displaced by the time the convention was signed; in all, roughly 1.2 million people moved to Greece and around 400,000 to Türkiye. The exchange uprooted communities that had lived in place for centuries — Turkish-speaking Orthodox Christians from Cappadocia and Greek-speaking Muslims from Crete among them — and its memory remains strong on both sides of the Aegean.
In Türkiye the war is remembered as a national liberation struggle, and it is the founding narrative of the Republic. Its main dates are public holidays or commemorations: 19 May (Commemoration of Atatürk, Youth and Sports Day), 23 April (National Sovereignty and Children's Day), 30 August (Victory Day) and 29 October (Republic Day). Mustafa Kemal's long 1927 speech, the Nutuk, set out an influential account of the struggle from his own perspective. In Greece the defeat is remembered as the "Asia Minor Catastrophe", which brought a refugee crisis that transformed Greek society. Historians today generally situate the war within the longer Ottoman collapse from 1912 onwards, a decade of almost continuous war, forced migration and mass violence across the region.
It is usually dated from Mustafa Kemal's landing at Samsun on 19 May 1919 to the Treaty of Lausanne on 24 July 1923, though the main fighting ended with the Armistice of Mudanya in October 1922. The Republic was proclaimed on 29 October 1923.
The nationalist forces fought Greece in western Anatolia, Armenia in the east and France in the south, while Britain and Italy occupied parts of the country. They also faced revolts at home and opposition from the sultan's government in Istanbul.
Sèvres was the peace treaty signed by the Ottoman government in August 1920. It would have partitioned Anatolia among Greece, Armenia and Allied zones of influence and placed the Straits under international control. It was never ratified and was replaced by the Treaty of Lausanne.
Fought from late August to mid-September 1921 near Ankara, Sakarya halted the Greek advance and is generally seen as the turning point of the war. Afterwards the Assembly gave Mustafa Kemal the title Gazi and the rank of marshal, and foreign powers began to deal with Ankara.
Signed on 24 July 1923, the Treaty of Lausanne recognised Turkish sovereignty over roughly the borders of modern Türkiye, abolished the capitulations and set out minority protections. A separate convention provided for the compulsory population exchange between Greece and Türkiye.
Roughly 1.2 million Orthodox Christians moved from Anatolia to Greece and around 400,000 Muslims moved from Greece to Türkiye, many of the former having already fled before the convention was signed in January 1923. Religion, not language, determined who was exchanged.
Related guides: The Gallipoli Campaign (1915–16), Timeline of Turkish History.