Darius III. had reached the dangerous condition of a very rich but not a warlike king; when then, he, by means of his wealth, incited other nations to make war upon Alexander, King of Macedonia, this great conqueror determined to attack Persia—a feat which he accomplished with so much success that he everywhere defeated the Persians, who for upwards of a hundred years were, in a great measure, under the yoke of Greece. In more modern times Persia has been invaded by the Tartars, a vagrant race of hunters and shepherds who were warlike and organized enough to subjugate Persia. With the exception of the early wars with the Greeks already referred to, the Persians, up to the year 1700, had not met in battle any of the armies of Europe. Peter the Great of Russia had, however, for a long time been desirous of extending his territory to the banks of the Caspian Sea, and had merely waited for a pretext to wage war with Persia. He did not seek an opportunity in vain, for a Russian caravan returning from China was plundered by the Persians, and this offence so irritated the Russian autocrat that he put himself at the head of his army, sailed from the Volga, and landed at Daghestan. Shortly after hostilities ceased, and Russia obtained from the Persians the towns of Baku, Derbund, and several provinces. During this period the Persians were also at war with the Afghans, who had invaded Persia and had been the cause of much misery. The late Czar Nicholas of Russia had no sooner ascended the throne than he commenced war with Persia, and at length, in 1828, concluded a treaty by which he gained several provinces. About the years 1836, 1837, a collision took place between the Persians and the Afghans. It was the object of the Persians to gain possession of the district of Herat. Now this district lies on the north-west of India, and may be called one of the barriers to our Eastern Empire, and as such it is essential to be preserved as an independent state. In July, 1837, the Persians marched an army against the Afghans, and, after a siege of ten days, succeeded in capturing Ghorian, and in December commenced the siege of Herat. Various remonstrances had been made to the Persians by the British authorities in connexion with the attack upon Herat, but without avail, and they merely had the effect of making the English unpopular. At this time a confidential messenger bearing despatches for the British minister was insulted and detained by the Persians. This and one or two other similar proceedings on the part of the Persians, in addition to their attack upon our then allies the Afghans, rendered amicable communications with them out of place, so that in June, 1838, our minister quitted the Persian court and ceased any friendly communication with the Persians.