Its natural boundary was defined by the Paropamisus, and only eighty miles beyond them lay Herāt. This city had played a great part in history. It was regarded as the key to Afghanistān; the only serious obstacle to a successful invasion of India from the north-west; and its citadel had been fortified in 1838 under the supervision of British officers. Nor was the importance of Herāt confined to its strategic position. It was the emporium of Central Asian trade, and the centre of a well-watered and fertile country. Thus the value to Russia of her latest acquisition was immense. In Merv she possessed a region which had been once the most fertile on the world’s surface, and needed but settled government to resume its ancient importance. The ill-defined area which she claimed to the south of the Merv oasis commanded the richest province of Persia and the north of Afghanistān. It was inevitable that the news of its impending appropriation should excite a storm of indignation in England, where every step of the Russian advance was watched with the keenest suspicion. An attempt to propitiate public feeling had been made as far back as 1882, when Russia proposed a joint commission to demarcate the northern boundary of Afghanistān, and at that time she would doubtless have accepted a line drawn from Khwāja Sālih on the Oxus to Sarakhs. But the Government then in power was not inclined to raise so delicate a question, and it was not until June 1884, when the situation had been radically modified by the conquest of Turkomania, that the proposal found acceptance. A joint commission was appointed in July, charged with the duty of laying down the disputed boundary. It was headed on the British side by General Sir Peter Lumsden, who had won distinction in India; while General Zelenoi was directed to watch over the interests of Russia. Sir Peter traversed Afghanistān, with the Amīr `Abd er-Rahmān’s permission, escorted by a little army of 500 strong with twice as many camp followers. This demonstration, for such it was, excited the suspicion of Lieutenant-General Komaroff,[636] the military governor of Transcaspia, and General Zelenoi was directed to return to Tiflis. In the meantime the explorations of Lessar in the valleys of the Murghāb and Kushk had led Russia to modify her claims. It was contended at the conference which followed that she should be allotted an ethnological frontier, based on the submission rendered by the Sāriks inhabiting the Panjdih oasis. The British representative, on the other hand, declined to recognise any other boundary than one based on natural conditions which excluded from Russian sway all territory south of an imaginary line drawn from Old Sarakhs to Khwāja Sālih on the Oxus. The Gordian knot was cut by the Afghans, who, encouraged by the presence on the Murghāb of the small British force attending Sir Peter Lumsden, moved northwards and occupied Bālā Murghāb and the disputed oasis of Panjdih.