The Persian campaign or invasion of Iran (Persian: اشغال ایران در جنگ جهانی اول) was a series of military conflicts between the Ottoman Empire, British Empire and Russian Empire in various areas of what was then neutral Qajar Iran, beginning in December 1914 and ending with the Armistice of Mudros on 30 October 1918, as part of the Middle Eastern Theatre of World War I. The fighting also involved local Persian units, who fought against the Entente and Ottoman forces in Iran. The conflict proved to be a devastating experience for Persia. Over 2 million Persian civilians died in the conflict, mostly due to the Persian famine of 1917–1919, influenced by British and Russian actions. The Qajar government's inability to maintain the country's sovereignty during and immediately after the First World War led to a coup d'état in 1921 and Reza Shah's establishment of the Pahlavi dynasty.
Background
Persia declared its neutrality during the outbreak of the First World War. Despite this, the country quickly became affected by the pre-war rivalry between the Allies and the Central Powers. Foreign interests in Persia were primarily driven by its strategic location between British India, Imperial Russia, Afghanistan, and the Ottoman Empire, as well as the country's oil reserves, which were first discovered on 26 May 1908. In the Anglo-Russian Treaty of 1907, the Russian and British governments agreed to divide Persia into three regions, with the Russians laying claim to northern Persia, the part adjacent to their previously conquered territories in the Transcaucasia, and the British claimed the south which bordered British India (a third region was left as a buffer zone). The 1907 treaty capped off several decades of the Great Game between the Russians and British. The treaty was signed at a time when German imperial expansion into the region was underway and the agreement served both Russia and Britain by providing a counterweight to increasing German regional influence and potential future expansion into the region.
The German Empire established its Intelligence Bureau for the East on the eve of World War I, dedicated to promoting and sustaining subversive and nationalist agitations in British India and the Persian and Egyptian satellite states. The bureau was involved in intelligence and subversive missions to Persia and Afghanistan to dismantle the Anglo-Russian Entente. The bureau's operations in Persia were led by Wilhelm Wassmuss. The Germans hoped to free Persia from British and Russian influence and to further create a wedge between Russia and the British, eventually leading to an invasion of British India by locally organised armies.
The Ottoman intervention in the Persian theatre was primarily driven by the necessity to neutralise escalating threats to the flanks of the Sixth Army. Following diplomatic pressure from the British Raj, which feared the influence of Pan-Islamism on the Indian Muslim population, the Russian Empire was urged to deploy significant forces along the Tehran–Hamadan–Khanaqin axis. This maneuver was strategically designed to allow Russian Caucasian corps to advance toward Mosul and Baghdad with minimal resistance.
The operational situation deteriorated when the 1st Russian Caucasian Corps seized the Paytak Pass, forcing the detachment under Miralay Arthur Bopp to retreat from Qasr-e Shirin toward Khanaqin. This retreat directly jeopardised the logistical lines of the Ottoman Sixth Army, necessitating the deployment of larger formations to the Persian front to mitigate the risk of encirclement. Despite the expanding British presence in Mesopotamia, Enver Pasha, the Deputy Commander-in-Chief, prioritised the Russian threat in Persia over the British forces on the Iraq front. He advocated for the redeployment of the XIII Corps from the Tigris sector to the Persian theatre. Influenced by intelligence reports from Nizam-us Saltana and Miralay Arthur Bopp—which the Sixth Army Command perceived as critical despite their later characterisation as exaggerated—Ottoman leadership shifted its focus toward implementing decisive countermeasures in Western Persia.
Beyond immediate tactical requirements, the Ottoman military's strategic goal was to disrupt Russian and British access to the hydrocarbon resources around the Caspian Sea. While aligned with German interests to undermine Entente influence, the Ottoman Ministry of War pursued a distinct regional agenda. Enver Pasha envisioned that a decisive victory in the key cities of Persia would secure a corridor to Azerbaijan, Central Asia, and potentially the borders of British India.
This initiative formed a core component of Enver Pasha's Pan-Turanian project, which sought to establish an extended network of nationalistic states independent of European colonial influence. Strategically, this position was based on the assumption that European powers lacked the resources to sustain their colonial administrations amidst the strains of a global war. Central to this objective was countering the Anglo-Persian Oil Company, which held exclusive rights to petroleum deposits throughout the Persian Empire, except in the northern provinces. By targeting these assets, the Ottoman leadership aimed to dismantle the economic foundation of British maritime power—specifically the oil supply for the Royal Navy—while expanding Ottoman political influence toward the East.
Forces
The Persian forces were established around certain districts, and not one single force. Each district furnished its own battalion and each province had several battalions. Each district depending on the tribal grouping furnished one or sometimes two battalions usually under their own chiefs. The strength of battalions was from 600 to 800. They had artillery batteries whose strength ranged from four to eight guns. Irregular troops amounted to about 50,000 in each district, with ranks composed of tribal horsemen and an uncertain number of footmen, all poorly armed. It was not uncommon of the chiefs, who controlled the battalions, to change sides. Some of these forces were Qashqai, Tangistani, Laristani, and Khamseh tribesmen. There was also the Persian Central Government Gendarmerie, which had Swedish officers and consisted of about 6,000 troops, of which only 2,000 were mounted. They were in six regiments, each of nine battalions, and their armament included Mauser rifles, twelve machine guns, and four mountain guns. The Persian forces were dispersed at Tehran, Qazvin, and Hamadan with the objective of keeping the country's main roads, which covered an estimated distance of 930 miles, under government control.
In late 1914, Enver Pasha gave orders to Lt. Col. Kâzım Bey, commander of the 1st Expeditionary Force (11 December), and Lt. Col. Halil Bey, commander of the 5th Expeditionary Force (25 December): "Your duty is to move with your division towards Persia and proceed through Tabriz to Dagestan, where you will ignite a general rebellion and repulse the Russians from the shores of the Caspian Sea."
The German operations were carried out by Wilhelm Wassmuss and Count Kanitz. Wassmuss, known as the German Lawrence, was a German consular official in Persia who loved the desert, and wore the flowing robes of a desert tribesman. He persuaded his superiors in Constantinople that he could lead Persian tribes in a revolt against Britain.
In 1914, the British Indian Army had several units located in the southern influence zone; its officers were experienced in fighting tribal forces through decades of conflict on the North-Western Frontier. In 1916, the British government formed the South Persian Rifles to protect their interests in Persia. At the end of 1917, a British force headed by Major-General Lionel Dunsterville was established. He arrived to take command in Baghdad on 18 January 1918. The British troops of Dunsterville eventually numbered about 1,000. They were supported by a field artillery battery, machine gun section, three armoured cars, and two airplanes. Together with mobile field hospitals, staff officers, headquarters staff, etc., the total force must have numbered about 1,300. Dunsterville was ordered to "proceed from Mesopotamia through Persia to the port of Anzali, then board ship to Baku and onwards."
Russia already had forces in Persia when the war began. The Persian Cossack Brigade and a small contingent of the Russian Caucasus Army under the Armenian General Tovmas Nazarbekian were stationed there. The Cossack Brigade consisted of eight squadrons, a small battalion of infantry and a horse battery of six Krupp guns; their total strength did not exceed 2,000. Besides this force, in 1912 Russia obtained the formal consent of the Persian government to the formation of a similar Cossack Brigade at Tabriz under Russian officers. Its formation was a condition for the withdrawal of Russian troops from Iranian Azerbaijan, which, at the onset of the war, Russia had not implemented. The Russians also moved one detachment of Armenian volunteer units under the command of Andranik Ozanian to the region.
Battle zone
The engagements were in Iranian Azerbaijan, comprising the modern provinces of East Azerbaijan, West Azerbaijan, and Ardabil, and including cities such as Tabriz, Urmia, Ardabil, Maragheh, Marand, Mahabad, and Khoy.
Operations
Prelude
The central Persian government had difficulties in establishing order before the war. In a single year; the Qashqai tribesmen, the most powerful in southern Persia, defied the governor-general and raided in Fars, as did the Boyer Ahmad-i tribesmen; the Khamseh tribesmen raided the caravan routes in Kermān Province; and other tribes raided in Fars, Yazd Province and Kermān Province from time to time. The government-controlled gendarmerie had gradually established themselves, although not wholly, and engaged a number of tribesmen. The authorities constructed posts along the routes which they held at the outbreak of war.
Russia maintained forces in northern Persia, ostensibly to protect the Armenian and Assyrian Christians. Tabriz was occupied in 1909; Urmia and Khoi in 1910. This measure enabled the Russians not only to control Persia, but also to secure the road from their rail-head at Djoulfa to the Ottoman province of Van through Khoi.
On 28 July 1914, the First World War began. At first the Ottoman Empire did not take any serious action. However, the security of the region began to decline even before the Russian-Ottoman conflict. Disturbances began along the border. A notable attack was made on Urmia, ostensibly by Kurdish tribesmen. About the same time the Russians closed the Ottoman consulates in Urmia, Tabriz and Khoi, and expelled Kurds and other Sunni Muslims from the villages around Urmia. Arms were given at the same time to some of the Armenians and Assyrians. Russian authorities distributed 24,000 rifles to some of the Kurdish tribesmen that sided with them in Persia and Van Province. Russian-Ottoman conflicts began with the Bergmann Offensive on 2 November 1914.
Late 1914
In December 1914, General Myshlaevsky ordered a withdrawal from Persia at the height of the Battle of Sarikamish. Only one brigade of Russian troops, under the command of General Nazarbekoff, and one battalion of Armenian volunteers scattered throughout Salmast and Urmia remained. Contact was limited to skirmishes on the border of northern Persia. The presence of Russian cavalry units kept them quiet. Enver established [one division] troops from conscripted at Constantinople [25 December]. This unit was given under the command of Khalil Bey. While [K?]Halil Bey's troops were preparing for the operation, a small group had already crossed the Persian frontier. After repulsing a Russian offensive toward Van, Van Gendarmerie Division [commanded by Major Ferid], a lightly equipped paramilitary formation, had chased the enemy into Persia.
On 14 December 1914, Van Jandarma Division occupied the city of Qotur. Later, proceeded towards Khoy. It was supposed to keep this passage open to Kâzım Bey (5th Expeditionary Force) and Halil Bey units (1st Expeditionary Force) who were to move towards Tabriz from the bridgehead established at Qotur. However, the Battle of Sarıkamısh depleted the Ottoman forces and these forces to be deployed to Persia were needed elsewhere. On 10 January, the 5th Expeditionary Force, which was on the way to Persia, was rerouted north to the Third Army and soon it was followed by the 1st Expeditionary Force.
1915
In 1915, Wilhelm Wassmuss conferred with local chiefs and distributed pamphlets urging revolt. He was arrested by a local chief, and turned over to the British, but managed to escape. He hoped to incite a revolt through pro-German members of the Persian government, in conjunction with an Ottoman advance towards Kermanshah and Hamadan.