At this period Persia was suffering all the disorders of anarchy. The Turks had possessed themselves of all its western provinces up to the foot of the Caucasus; whilst the mountaineers, availing themselves of the distracted state of the country, made bloody inroads upon Georgia and the adjacent regions. The Lesghis, now one of the most formidable tribes of the Caucasus, ravaged the plains of Shirvan, in 1712, reduced the towns and villages to ashes, and massacred, according to Russian writers, 300 merchants, subjects of the empire, in the town of Shamaki. These acts of violence afforded Peter the Great an opportunity which he did not let slip. Under the pretence of punishing the Lesghis, and protecting the Shah of Persia against them, he prepared to make an armed intervention in the trans-Caucasian provinces. A formidable expedition was fitted out. A flotilla, constructed at Casan, arrived at the mouths of the Volga, and on the 15th of May, 1722, the emperor began his march at the head of 22,000 infantry, 9000 dragoons, and 15,000 Cossacks and Kalmucks. The transports coasted the Caspian, whilst the army marched by the Daghestan route, the great highway successively followed by the nations of the north and the south in their invasions. Thus it was that the Russians entered the Caucasus, and the valleys of those inaccessible mountains resounded, for the first time, to the war music of the Muscovite. The occupation of Ghilan and Derbent, and the siege of Bakou were the chief events of this campaign. Turkey, dismayed at the influence Russia was about to acquire in the East, was ready to take up arms; but Austria, taking the initiative in Europe, declared for the policy of the tzar, and vigorously resisted the hostile tendencies of the Porte. Russia was thus enabled to secure, not only Daghestan and Ghilan, but also the surrender of those provinces in which her armies had never set foot. In the midst of these events, Peter died when on the eve of consolidating his conquests, and before he had completed his negotiations with Persia and Turkey. His grand commercial ideas were abandoned after his death; the policy of the empire was directed solely towards territorial acquisition, and the tzars only obeyed the strong impulse, that, as if by some decree of fate, urges their subjects towards the south. Thenceforth the trans-Caucasian provinces were considered only a point gained for intervention in the affairs of Persia and Turkey, and for ulterior conquests in the direction of Central Asia. The rise of the celebrated Nadir Shah, who possessed himself of all the ancient dominions of Persia, for a while changed the face of things. Russia, crippled in her finances, withdrew her troops, gave up her pretensions to the countries beyond the Caucasus, acknowledged the independence of the two Kabardas by the treaty of Belgrade, and even engaged no longer to keep a fleet on the Sea of Azof.
A religious mission sent to the Ossetans, who occupy the celebrated defiles of Dariel, was the only event in the reign of Elizabeth, that regarded the regions we are considering. Hardly any conversions were effected, but the Ossetans, to a certain extent, acknowledged the supremacy of Russia: this satisfied the real purpose of the mission, for the first stone was thereby laid on the line which was to become the great channel of communication between Russia and her Asiatic provinces.
Schemes of conquest in the direction of Persia were resumed with vigour under Catherine II., and were carried out with more regularity. The first thing aimed at was to protect the south of the empire against the inroads of the Caucasians, and to this end the armed line of the Kouban and the Terek was organised and finished in 1771. It then numbered sixteen principal forts, and a great number of lesser ones and redoubts. Numerous military colonies of Cossacks, were next settled on the banks of the two rivers for the protection of the frontiers. While these preparations were in hand, war broke out with Turkey. Victorious both by sea and land, Catherine signed, in 1774, the memorable treaty of Koutchouk Kainardji, which secured to her the free navigation of the Black Sea, the passage of the Dardanelles, the entry of the Dniepr, and, moreover, conceded to her in the Caucasus, the sovereignty over both Kabardas.