(fäth älē' shä', fät) , also spelled Feth Ali Shah, 1762–1834, shah of Persia (1797–1834), nephew and successor of Aga Muhammad Khan, founder of the Qajar dynasty. Most of his reign was spent in internal and external warfare. He managed to maintain himself against other claimants to the throne but was not so fortunate in his wars with Russia. He sought to enlist aid from Napoleon, who was then contemplating an attack on India, but the shah's hopes were dashed when Napoleon signed the Treaty of Tilsit (1807) with Russia. Fath Ali subsequently turned to England, but English influence failed to protect Persia from Russian encroachments. The shah's attempt to reconquer Georgia proved disastrous, and the Treaty of Gulistan (1813) and the Treaty of Turkmanchai (1828) deprived Persia of the Caucasus and marked a downward trend in Persian power.