It is necessary now to revert, for a little space, to the progress of affairs in Western Asia. Whilst the Suddozye Princes in Afghanistan had been gradually relaxing their hold of the Douranee Empire, Persia had been still struggling against Russian encroachment—still entangled in the meshes of a long and harassing war. Though enfeebled by the paramount necessity of concentrating the resources of the empire on the great European contest, which demanded the assertion of all her military strength, the aggressive tendencies of the great northern power were not to be entirely controlled. Little could she think of remote acquisitions of territory in Georgia, whilst the eagles of Napoleon were threatening her very existence at the gates of Moscow itself. Still with little intermission, up to the year 1813, the war dragged languidly on. Then the good offices of Great Britain were successfully employed for the re-establishment of friendly relations between the two contending powers;[88] and a treaty, known as the treaty of Goolistan, was negotiated between them. By this treaty 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. During these wars, which were carried on with varying success, the Persian troops upon more than one occasion had been led to the charge by English officers of approved gallantry and skill. Accompanying General Malcolm to Persia in 1810, they were retained in the country by Sir Harford Jones; and were very soon busily employed in drilling and disciplining the infantry and artillery of the Persian Prince.[89] Of these officers, the most conspicuous were Captain Christie and Lieutenant Lindsay, who led into the field the battalions which they had instructed, and more than once turned the tide of victory against their formidable European opponents.[90]