From 1885 onwards the attention of the Indian government was increasingly devoted to the north-west frontier. Between the years 1885 and 1895 there were delimited at various times by joint commissions the Russo-Afghan frontier between the Oxus and Sarakhs on the Persian frontier, the Russo-Afghan frontier from Lake Victoria to the frontier of China and the Afghan-Indian frontier from the Kunar river to a point in the neighbourhood of the Nawa Kotal. To the westward, after various disagreements and two military expeditions, the territories comprising the Zhob, Barhan and Bori valleys, occupied by Pathan tribes, were in 1890 finally incorporated in the general system of the Trans-Indus protectorate. About the same time in the extreme north the post of British resident in Gilgit was re-established, and the supremacy of Kashmir over the adjoining petty chiefships of Hunza-Nagar was enforced (1891-1892). In 1893 the frontiers of Afghanistan and British India were defined by a joint agreement between the two governments, known as the Durand agreement. There followed on the part of the British authorities, interference in Chitral, ending in an expedition in 1895 and the ejection of the local chiefs in favour of candidates amenable to British influence. A more formidable hostile combination, however, awaited the government of India. By the agreement of 1893 with the amir most of the Waziri clan and also the Afridis had been left outside the limits of the amir's influence and transferred to the British zone. Soon after that date the establishment by the British military authorities of posts within the Waziri country led to apprehension on the part of the local tribesmen. In 1895 the occupation of points within the Swat territory for the safety of the road from India to Chitral similarly roused the suspicion of the Swatis. The Waziris and Swatis successively rose in arms, in June and July 1897, and their example was followed by the Mohmands. Finally, in August the powerful Afridi tribe joined the combination and closed the Khyber Pass, which runs through their territory, and which was held by them, on conditions, in trust for the government of India. This led to the military operations known as the Tirah campaign, which proved very costly both in men and money. The currency.