'By this treaty,' says Kaye, 'Persia ceded to Russia all her acquisitions on the South of the Caucasus, and agreed to maintain no naval force on the Caspian Sea; whilst Russia entered into a vague engagement to support, in the event of a disputed succession, the claims of the heir-apparent against all competitors for the throne.' British officers remained in Persia, doing little good. Then came again war with Russia in 1826, followed by the complete defeat of the Persians, and in 1828 by the treaty of TurkmánChai. By the treaty of TurkmánChai the Caspian became a Russian lake; and two provinces were wrested from Persia. Neither men nor money had been furnished by Mr. Canning to Persia during this war, under the treaties of 1814, though both had been anxiously asked for. Teherán passed, and has remained, under the predominant influence of Russia. From that moment the countries which lie on the North-West Frontier of India again came into the foreground of the field of British and Indian politics. The risk which had led to the treaties of 1809 and 1814 reappeared; but the Power with whom we had entered into alliance to avert it was now likely to add to its imminence. For Muhammad Sháh, who, in 1834, succeeded to the throne of Persia, was understood to be wholly under Russian influence. Far from being a buckler to Great Britain against invasion of India, he was now to prove the weapon of offence. He at once renewed the project of attacking Herát, which, under the guidance of his father, the late Crown
