SINCE it was the British complications with Persia which mainly furnished what pretext there was for the invasion of Afghanistan by an Anglo-Indian army in 1839, some brief recital is necessary of the relations between Great Britain and Persia prior to that aggression. By a treaty, concluded between England and Persia in 1814, the former state bound itself, in case of the invasion of Persia by any European nation, to aid the Shah either with troops from India or by the payment of an annual subsidy in support of his war expenses. It was a dangerous engagement, even with the caveat rendering the undertaking inoperative if such invasion should be provoked by Persia. During the fierce struggle of 1825-7, between Abbas Meerza and the Russian General Paskevitch, England refrained from supporting Persia either with men or with money, and when prostrate Persia was in financial extremities because of the war indemnity which the treaty of Turkmanchai imposed upon her, England took advantage of her needs by purchasing the cancellation of the inconvenient obligation at the cheap cost of about £300,000. It was the natural result of this transaction that English influence with the Persian Court should sensibly decline, and it was not less natural that in conscious weakness Persia should fall under the domination of Russian influence. Futteh Ali, the old Shah of Persia, died in 1834, and was succeeded by his grandson Prince Mahomed Meerza, a young man who inherited much of the ambition of his gallant father Abbas Meerza. His especial aspiration, industriously stimulated by his Russian advisers, urged him to the enterprise of conquering the independent principality of Herat, on the western border of Afghanistan. Herat was the only remnant of Afghan territory that still remained to a member of the legitimate royal house. Its ruler was Shah Kamran, son of that Mahmoud Shah who, after ousting his brother Shah Soojah from the throne of Cabul, had himself been driven from that elevation, and had retired to the minor principality of Herat. The young Shah of Persia was not destitute of justification for his designs on Herat. That this was so was frankly admitted by Mr Ellis, the British envoy to his Court, who wrote to his Government that the Shah had fair claim to the sovereignty of Afghanistan as far as Ghuznee, and that Kamran's conduct in occupying part of the Persian province of Seistan had given the Shah 'a full justification for commencing hostilities against Herat.' The serious phase of the situation for England and India was that Russian influence was behind Persia in this hostile action against Herat. Mr Ellis pointed out that in the then existing state of relations between Persia and Russia, the progress of the former in Afghanistan was tantamount to the advancement of the latter. But unfortunately there remained valid an article in the treaty of 1814 to the effect that, in case of war between the Afghans and the Persians, the English Government should not interfere with either party unless when called on by both to mediate. In vain did Ellis and his successor M'Neill remonstrate with the Persian monarch against the Herat expedition. An appeal to St Petersburg, on the part of Great Britain, produced merely an evasive reply. How diplomatic disquietude had become intensified may be inferred from this, that whereas in April 1836 Ellis wrote of Persia as a Russian first parallel of attack against India, Lord Auckland, then Governor-General of India, directed M'Neill, in the early part of 1837, to urge the Shah to abandon his enterprise, on the ground that he (the Governor-General) 'must view with umbrage and displeasure schemes of interference and conquest on our western frontier.'