In 1852 an attempt was made on Nāṣer al-Dīn’s life by two Bābīs (members of a religious sect considered heretical); he responded with a fierce, cruel, and prolonged persecution of the sect.Unable to regain territory lost to Russia in the early 19th century, Nāṣer al-Dīn sought compensation by seizing Herāt, Afghanistan, in 1856. Great Britain regarded the move as a threat to British India and declared war on Iran, forcing the return of Herāt as well as Iranian recognition of the kingdom of Afghanistan.