Great Game participant Russian Empire
First signs of possible India invasion
At the start of the 19th century, the Indian subcontinent was ruled in part by independent princely states and in part by the company rule of the British East India Company. During the 19th century, a political and diplomatic confrontation developed between Britain and Russia over Afghanistan which would become known as The Great Game. Russia's foreign policy was driven by the perspective that Britain would develop and control commercial and military inroads into Central Asia, and Britain's foreign policy was based on expectations of Russia adding the "jewel in the crown", India, to the vast empire that Russia was building in Asia. This resulted in an atmosphere of distrust and the constant threat of war between the two empires. If Russia were to gain control of the Emirate of Afghanistan, it might then be used as a staging post for a Russian invasion of India, was the British line of thinking.Napoleon had proposed a joint Franco-Russian invasion of India to tsar Paul I of Russia. Expecting a future action by the British against Russia and her allies in Europe, Paul decided in 1801 to make the first move towards where he believed the British Empire was weakest. He wrote to the Ataman of the Don Cossacks Troops, Cavalry General Vasily Petrovich Orlov, directing him to march to Orenburg, conquer the Central Asian Khanates, and from there invade India. Paul was assassinated in the same year, and the invasion was terminated. 
Historian Peter Hopkirk wrote that Tsar Paul had not been able to obtain a detailed map of India until the Cossacks' departure from Orenburg. He quotes the Tsar as instructing Orlov: "My maps only go as far as Khiva and the River Oxus. Beyond these points it is your affair to gain information about the possessions of the English, and the condition of the native population subject to their rule". The British public learned about the incident years later, but it firmly imprinted on the popular consciousness, contributing to feelings of mutual suspicion and distrust associated with the Great Game. Hugh Seton-Watson observed that "the grotesque plan had no military significance, but at least showed its author's state of mind". Hopkirk remarked that "no serious thought or study has been given to this wild adventure".Napoleon tried to persuade Paul's son, Tsar Alexander I of Russia, to invade India; however Alexander resisted. In 1807, Napoleon dispatched General Claude Matthieu, Count Gardane on a French military mission to Persia, with the intention of persuading Russia to invade India. In response, Britain sent its own diplomatic missions in 1808, with military advisers, to Persia and Afghanistan under the capable Mountstuart Elphinstone, averting the possible French and Russian threat to India. However, Britain was left with concerns about being able to defend its colony on the subcontinent. At the time, Russia also went to war with Qajar Iran and invaded the Persian Caucasus from 1804-1813, adding to Britain's fears, while Russia was distracted mainly by the Napoleonic Wars.In 1810, British Lieutenant Henry Pottinger and Captain Charles Christie undertook an expedition from Nushki (Balochistan) to Isfahan (Central Persia) disguised as Muslims. The expedition was funded by the East India Company and was to map and research the regions of "Beloochistan" (Balochistan) and Persia because of concerns about India being invaded by French forces from that direction. After the disastrous French invasion of Russia in 1812 and the collapse of the French army, the threat of a French invasion through Persia was removed.
The shah of Iran, Fath-Ali Shah Qajar would become part of diplomatic intrigues about India. He first received limited British support in 1801 that was canceled after Russia's invasion of Persia in 1804. Fath-Ali then lent a promise to Napoleon in 1807 to theoretically invade British India in exchange for French military assistance (Gardane's mission) which fell through despite the Treaty of Finckenstein. When France allied with Russia at Tilsit in 1807, as Russia was still invading Iran, Fath-Ali Shah turned toward British diplomacy and alliance in 1809. The shah was also able to use a rivalry between the East India Company and the British Foreign Office, to garner more British aid. In the 1809 preliminary Treaty of Tehran, Persia agreed to stop any European or foreign army passing to India, while the British agreed to send a mission to train sixteen thousand Persian soldiers and, if Qajar Persia was invaded by a European state, pay a £100,000 subsidy to Persia, while attempting to mediate if at peace with Persia's enemy.: 167  Nevertheless, Russia would end up defeating Iran a few years later, with Britain mediating the treaty.