[7][11] The Qajar family played a pivotal role in the Unification of Iran (1779–1796), deposing Lotf 'Ali Khan, the last Shah of the Zand dynasty, and re-asserted Iranian sovereignty over large parts of the Caucasus.

[13] In the Caucasus, the Qajar dynasty permanently lost much territory[14] to the Russian Empire over the course of the 19th century, comprising modern-day eastern Georgia, Dagestan, Azerbaijan, and Armenia.

[15] Despite its territorial losses, Qajar Iran reinvented the Iranian notion of kingship[16] and maintained relative political independence, but faced major challenges to its sovereignty, predominantly from the Russian and British empires.

[21][22] The idea of the Guarded Domains illustrated a feeling of territorial and political uniformity in a society where the Persian language, culture, monarchy, and Shia Islam became integral elements of the developing national identity.

[23] The concept presumably had started to form under the Mongol Ilkhanate in the late 13th-century, a period in which regional actions, trade, written culture, and partly Shia Islam, contributed to the establishment of the early modern Persianate world.

[26] Based on the claims of the legend, Iranologist Gavin R. G. Hambly reconstructed the early history of the Qajars in a hypothetical manner, suggesting that they immigrated towards Anatolia or Syria following the collapse of the Ilkhanate in 1335.

[27] Like the other Oghuz tribes in Azerbaijan and eastern Anatolia during the rule of the Aq Qoyunlu, the Qajars likely also converted to Shia Islam and adopted the teachings of the Safavid order.

The great number of them also settled in Astarabad (present-day Gorgan, Iran) near the south-eastern corner of the Caspian Sea,[8] and it would be this branch of Qajars that would rise to power.

[41] A limited Russian contingent of two infantry battalions with four artillery pieces arrived in Tbilisi in 1784,[39] but was withdrawn in 1787, despite the frantic protests of the Georgians, as a new war against Ottoman Turkey had started on a different front.

For Agha Mohammad Khan, the resubjugation and reintegration of Georgia into the Iranian empire was part of the same process that had brought Shiraz, Isfahan, and Tabriz under his rule.

[39] It was therefore natural for Agha Mohammad Khan to perform whatever necessary means in the Caucasus in order to subdue and reincorporate the recently lost regions following Nader Shah's death and the demise of the Zands, including putting down what in Iranian eyes was seen as treason on the part of the vali of Georgia.

[44] Erekle appealed then to his theoretical protector, Empress Catherine II of Russia, asking for at least 3,000 Russian troops,[44] but he was ignored, leaving Georgia to fend off the Iranian threat alone.

[44] With half of the troop's Agha Mohammad Khan crossed the Aras river with, he now marched directly upon Tbilisi, where it commenced into a huge battle between the Iranian and Georgian armies.

[14] It was therefore also inevitable that Agha Mohammad Khan's successor, Fath Ali Shah (under whom Iran would lead the two above-mentioned wars) would follow the same policy of restoring Iranian central authority north of the Aras and Kura rivers.

The Qajar army suffered a major military defeat in the war, and under the terms of the Treaty of Gulistan in 1813, Iran was forced to cede most of its Caucasian territories comprising modern-day Georgia, Dagestan, and most of Azerbaijan.

At the time of the Russian invasion of Iran, some 80% of the population of Erivan Khanate in Iranian Armenia were Muslims (Persians, Turkics, and Kurds) whereas Christian Armenians constituted a minority of about 20%.

Naser al-Din Shah tried to exploit the mutual distrust between Great Britain and Russia to preserve Iran's independence, but foreign interference and territorial encroachment increased under his rule.

With the conclusion of the Treaty of Akhal on 21 September 1881, Iran ceased any claim to all parts of Turkestan and Transoxiana, setting the Atrek River as the new boundary with Imperial Russia.

Amir Kabir issued an edict banning ornate and excessively formal writing in government documents; the beginning of a modern Persian prose style dates from this time.

He hired French and Russian instructors as well as Iranians to teach subjects as different as Language, Medicine, Law, Geography, History, Economics, and Engineering, amongst numerous others.

However, until 1907 the Great Game rivalry was so pronounced that mutual British and Russian demands to the Shah to exclude the other, blocked all railroad construction in Iran at the end of the 19th century.

Popular demand to curb arbitrary royal authority in favor of the rule of law increased as concern regarding growing foreign penetration and influence heightened.

When the shah reneged on a promise to permit the establishment of a "house of justice", or consultative assembly, 10,000 people, led by the merchants, took sanctuary in June in the compound of the British legation in Tehran.

Most serious of all, the hope that the Constitutional Revolution would inaugurate a new era of independence from the great powers ended when, under the Anglo-Russian Entente of 1907, Britain and Russia agreed to divide Iran into spheres of influence.

To prevent this, on 20 December, Bakhtiari chiefs and their troops surrounded the Majles building, forced acceptance of the Russian ultimatum, and shut down the assembly, once again suspending the constitution.

The British Ambassador, George Head Barclay reported disapproval of this "reign of terror", though would soon pressure Persian ministers to officialize the Anglo-Russian partition of Iran.

[92] Though Qajar Iran had announced strict neutrality on the first day of November 1914 (which was reiterated by each successive government thereafter),[93] the neighboring Ottoman Empire invaded it relatively shortly after, in the same year.

In late 1915, due to pro-CP actions by Iranian gendarmerie (encouraged by Ahmad Shah Qajar and the Majlis), Russian forces in northwest Iran marched toward Tehran.

[104] At the time of Agha Mohammad Khan's death in 1797, his military was at its apex and counted 60,000 men, consisting of 50,000 tribal cavalry (savar) and 10,000 infantry (tofangchi) recruited from the sedentary population.

[108] In the late 18th century, during the final period of Shah Agha Mohammad Khan's reign, Iran (including the Khanates of the Caucasus) numbered some five to six million inhabitants.