title Aga Khan. When Mohammad Shah ascended the throne, on the advise of Qa'em Maqam, he appointed Agha Khan the governor of Kerman, a rebellious state that was governed by Shoja al-Saltanah, a brother of Hossein Ali Mirza. Agha Khan pacified the state but his governorship was short-lived; in 1837, he was recalled to Tehran and was replaced with Firouz Mirza, the shah's brother. Agha Khan raised arms and declared a rebellion against the shah, and withdraw with his forces to Bam. Mohammad Shah sent an army under the command of Sourab Khan; they besieged Bam and took severely injured brother of Agha Khan prisoner. After eight months, Agha Khan surrendered and was imprisoned; his belongings were plundered and his was not allowed to receive his religious due sent from India, Khurasan and Badakhshan. Agha Khan was a prisoner of the shah until 1838, when he was allowed to retreat to his familial lands in Mahallat. Herat campaign After asserting his authority, Mohammad Shah's main objective was to annex Herat. This alarmed Kamran Shah and promted him to attempt to gather neighboring tribes such as the Jamshidi, Tumani and Hazara in Herat to resist Mohammad in the event of a military campaign. These mobilizations alarmed the British government, which sent Alexander Burnes and Eldred Pottinger to Kabul and Herat respectively. Among Britain's concerns was Article 11 of the Treaty of Turkmenchay, which allowed Russia to establish consulates and trade missions with up to ten members throughout Iranian territory, implanting influence on Afghanistan and therefore becoming a threat to British India. The UK accused the Russian government of encouraging Iran to invade Herat. Iran wanted to retake of Herat partly because of Mohammad's desire to unite the Persian-speaking tribes of the Afghan highlands with Iran, and because wanted to free Iranian prisoners who were taken by Sunni tribes who lived near Khorasan. Conquest of Herat was also the first step in a plan to extend Iran's influence up to Amu Darya. In late 1836, Mohammad ordered his army to be mustered for the following spring. This gave John McNeill, the British envoy in Iran, time to arrange an agreement in which Herat would resume paying tributes. Yar Mohammad Khan, however, would not tolerate Iranian sovereignty and Kamran Shah would not withdraw unless the city was conquered. In 1837, Mohammad Shah marched on Herat. British officers were expelled from the Iranian army