Spreading over the Steppes of Tartary, they made frequent inroads upon the Russian territory, and in 1717 penetrated as far as Kazan. Surrounded, however, by tribes of Bashkirs, Calmucks, Zungars, and Nogais, the Kirghiz were continually attacking or being attacked, while their division into three hordes, the reason of which has never been fully accounted for, did not increase their warlike capabilities. Thus it happened that the great horde was completely subjugated by the powerful tribe of the Zungars, whose territory extended to the Chinese frontier; and it soon after became apparent that the middle and little hordes could not much longer continue to make a successful stand against the western tribes. In this emergency, Aboulkhair, the most celebrated of Kirghiz Khans, perceived the advantage of obtaining the protection of Russia. As, however, both hordes were excessively averse to any such proposal, the negotiations were carried on with great tact and secresy by Tevkelef, a Russian agent, who guaranteed to Aboulkhair the assistance of Russia, in order to enable him to carry his designs into execution. This, however, did not become necessary; the consent of the Kirghiz was ultimately obtained, partly through the persuasive eloquence of Tevkelef, and partly by the influence of Aboulkhair; and in 1734, the middle and little hordes were formally enrolled as subjects of the Empress Ann. The submission thus obtained was not of any very permanent character, and Kirilof was sent with a small body of troops into the Kirghiz Steppes to take measures, which should insure the permanent subjection of these tribes. His instructions afford us the first glimpse of the ulterior designs of Russia, and the means proposed for their execution. Kirilof was commanded at once to build a town and fort at the embouchure of the Ori; to assemble the Khans and ancients of the two hordes, and obtain from them, in the presence of their subjects, the oath of allegiance, and having succeeded in this, he was to preserve the obedience of the Kirghiz by gentleness or by force, by presents or by menaces, according to circumstances. The Ural was to be considered the boundary of the empire, and the newly-acquired subjects were strictly prohibited from crossing it. A caravan was to be despatched across the Steppes to Boukhara, with the least possible delay, and every effort was to be used in order to attract merchandise from every part of Asia. Kirilof was himself to examine the annexed country, in the hope of discovering mines. A port was to be established upon the Sea of Aral, and ships built upon the Ural, and kept ready to be transported thither as soon as the town should be built, and such terms made with the Kirghiz as would facilitate their conveyance, and that of the artillery with which they were to be provided.