HINDU KUSH ( Caucasus Indicus ) , a range of mountains in Central Asia. Throughout 500 m. of its length, from its roots in the Pamir regions till it fades into the Koh-i-Baba to the west of Kabul, this great range forms the water-divide between the Kabul and the Oxus basins, and, for the first 200 m. reckoning westwards, the southern boundary of Afghanistan. It may be said to spring from the head of the Taghdumbash Pamir, where it unites with the great meridional system of Sarikol stretching northwards, and the yet more impressive mountain barrier of Muztagh, the northern base of which separates China from the semi-independent territory of Kanjut. The Wakhjir pass, crossing the head of the Taghdumbash Pamir into the sources of the river Hunza, almost marks the tri-junction of the three great chains of mountains. As the Hindu Kush strikes westwards, after first rounding the head of an Oxus tributary (the Ab-i-Panja, which Curzon considers to be the true source of the Oxus), it closely overlooks the trough of that glacier-fed stream under its northern spurs, its crest at the nearest point being separated from the river by a distance which cannot much exceed 10 m. As the river is here the northern boundary of Afghanistan, and the crest of the Hindu Kush the southern boundary, this distance represents the width of the Afghan kingdom at that point.
Physiography.—For the first 100 m. of its length the Hindu Kush is a comparatively flat-backed range of considerable width, permitting the formation of small lakes on the crest, and possessing no considerable peaks. It is crossed by many passes, varying in height from 12,500 ft. to 17,500 ft., the lowest and the easiest being the well-known group about Baroghil, which has from time immemorial offered a line of approach from High Asia to Chitral and Jalalabad. As the Hindu Kush gradually recedes from the Ab-i-Panja and turns south-westwards it gains in altitude, and we find prominent peaks on the crest which measure more than 24,000 ft. above sea-level. Even here, however, the main central water-divide, or axis of the chain, is apparently not the line of highest peaks, which must be looked for to the south, where the great square-headed giant called Tirach Mir dominates Chitral from a southern spur. For some 40 or 50 m. of this south-westerly bend, bearing away from the Oxus, where the Hindu Kush overlooks the mountain wilderness of Badakshan to the west, the crest is intersected by many passes, of which the most important is the Dorah group (including the Minjan and the Mandal), which rise to about 15,000 ft., and which are, under favourable conditions, practicable links between the Oxus and Chitral basins.
From the Dorah to the Khawak pass (or group of passes, for it is seldom that one line of approach only is to be found across the Hindu Kush), which is between 11,000 and 12,000 ft. in altitude, the water-divide overlooks Kafiristan and Badakshan. Here its exact position is matter of conjecture. It lies amidst a wild, inaccessible region of snowbound crests, and is certainly nowhere less than 15,000 ft. above sea-level. There is a tradition that Timur attempted the passage of the Hindu Kush by one of the unmapped passes hereabouts, and that, having failed, he left a record of his failure engraved on a rock in the pass.
The Khawak, at the head of the Panjshir tributary of the Kabul river, leading straight from Badakshan to Charikar and the city of Kabul, is now an excellent kafila route, the road having been engineered under the amir Abdur Rahman’s direction, and it is said to be available for traffic throughout the year. From the Khawak to the head of the Ghorband (a river of the Hindu Kush which, rising to the north-west of Kabul, flows north-east to meet the Panjshir near Charikar, whence they run united into the plains of Kohistan) the Hindu Kush is intersected by passes at intervals, all of which were surveyed, and several utilized, during the return of the Russo-Afghan boundary commission from the Oxus to Kabul in 1886. Those utilized were the Kaoshan (the “Hindu Kush” pass par excellence), 14,340 ft.; the Chahardar (13,900 ft.), which is a link in one of the amir of Afghanistan’s high roads to Turkestan; and the Shibar (9800 ft.), which is merely a diversion into the upper Ghorband of that group of passes between Bamian and the Kabul plains which are represented by the Irak, Hajigak, Unai, &c. About this point it is geographically correct to place the southern extremity of the Hindu Kush, for here commences the Koh-i-Baba system into which the Hindu Kush is merged.
The general conformation of the Hindu Kush system south of the Khawak, no less than such fragmentary evidence of its rock composition as at present exists to the north, points to its construction under the same conditions of upheaval and subsequent denudation as are common to the western Himalaya and the whole of the trans-Indus borderland. Its upheaval above the great sea which submerged all the north-west of the Indian peninsula long after the Himalaya had massed itself as a formidable mountain chain, belongs to a comparatively recent geologic period, and the same thrust upwards of vast masses of cretaceous limestone has disturbed the overlying recent beds of shale and clays with very similar results to those which have left so marked an impress on the Baluch frontier. Successive flexures or ridges are ranged in more or less parallel lines, and from between the bands of hard, unyielding rock of older formation the soft beds of recent shale have been washed out, to be carried through the enclosing ridges by rifts which break across their axes. The Hindu Kush is, in fact, but the face of a great upheaved mass of plateau-land lying beyond it northwards, just as the Himalaya forms the southern face of the great central tableland of Tibet, and its general physiography, exhibiting long, narrow, lateral valleys and transverse lines of “antecedent” drainage, is similar. There are few passes across the southern section of the Hindu Kush (and this section is, from the politico-geographical point of view, more important to India than the whole Himalayan system) which have not to surmount a succession of crests or ridges as they cross from Afghan Turkestan to Afghanistan. The exceptions are, of course, notable, and have played an important part in the military history of Asia from time immemorial. From a little ice-bound lake called Gaz Kul, or Karambar, which lies on the crest of the Hindu Kush near its northern origin at the head of the Taghdumbash Pamir, two very important river systems (those of Chitral and Hunza) are believed to originate. The lake really lies on the watershed between the two, and is probably a glacial relic. Its contribution to either infant stream appears to depend on conditions of overflow determined by the blocking of ice masses towards one end. It marks the commencement of the water-divide which primarily separates the Gilgit basin from that of the Yashkun, or Chitral, river, and subsequently divides the drainage of Swat and Bajour from that of the Chitral (or Kunar). The Yashkun-Chitral-Kunar river (it is called by all three names) is the longest affluent of the Kabul, and it is in many respects a more important river than the Kabul. Throughout its length it is closely flanked on its left bank by this main water-divide, which is called Moshabar or Shandur in its northern sections, and owns a great variety of names where it divides Bajour from the Kunar valley. It is this range, crowned by peaks of 22,000 ft. altitude and maintaining an average elevation of some 10,000 ft. throughout its length of 250 m., that is the real barrier of the north—not the Hindu Kush itself. Across it, at its head, are the glacial passes which lead to the foot of the Baroghil. Of these Darkot, with a glacial staircase on each side, is typical. Those passes (the Kilik and Mintaka) from the Pamir regions, which lead into the rocky gorges and defiles of the upper affluents of the Hunza to the east of the Darkot, belong rather to the Muztagh system than to the Hindu Kush. Other passes across this important water-divide are the Shandur (12,250 ft.), between Gilgit and Mastuj; the Lowarai (10,450 ft.), between the Panjkora and Chitral valleys; and farther south certain lower crossings which once formed part of the great highway between Kabul and India.
Deep down in the trough of the Chitral river, about midway between its source and its junction with the Kabul at Jalalabad, is the village and fort of Chitral (q.v.). Facing Chitral, on the right bank of the river, and extending for some 70 m. from the Hindu Kush, is the lofty snow-clad spur of the Hindu Kush known as Shawal, across which one or two difficult passes lead into the Bashgol valley of Kafiristan. This spur carries the boundary of Afghanistan southwards to Arnawai (some 50 m. below Chitral), where it crosses the river to the long Shandur watershed. South of Arnawai the Kunar valley becomes a part of Afghanistan. The value of Chitral as an outpost of British India may be best gauged by its geographical position. It is about 100 m. (direct map measurement) from the outpost of Russia at Langar Kisht on the river Panja, with the Dorah pass across the Hindu Kush intervening. The Dorah may be said to be about half-way between the two outposts, and the mountain tracks leading to it on either side are rough and difficult. The Dorah, however, is not the only pass which leads into the Chitral valley from the Oxus. The Mandal pass, a few miles south of the Dorah, is the connecting link between the Oxus and the Bashgol valley of Kafiristan; and the Bashgol valley leads directly to the Chitral valley at Arnawai, about 50 m. below Chitral. Nor must we overlook the connexion between north and south of the Hindu Kush which is afforded by the long narrow valley of the Chitral (or Yashkun) itself, leading up to the Baroghil pass. This route was once made use of by the Chinese for purposes of pilgrimage, if not for invasion. Access to Chitral from the north is therefore but a matter of practicable tracks, or passes, in two or three directions, and the measure of practicability under any given conditions can best be reckoned from Chitral itself. By most authorities the possibility of an advance in force from the north, even under the most favourable conditions, is considered to be exceedingly small; but the tracks and passes of the Hindu Kush are only impracticable so long as they are left as nature has made them.
Historical Notices.—Hindu Kush is the Caucasus of Alexander’s historians. It is also included in the Paropamisus, though the latter term embraces more, Caucasus being apparently used only when the alpine barrier is in question. Whether the name was given in mere vanity to the barrier which Alexander passed (as Arrian and others repeatedly allege), or was founded also on some verbal confusion, cannot be stated. It was no doubt regarded (and perhaps not altogether untruly) as a part of a great alpine zone believed to traverse Asia from west to east, whether called Taurus, Caucasus or Imaus. Arrian himself applies Caucasus distinctly to the Himalaya also. The application of the name Tanais to the Syr seems to indicate a real confusion with Colchian Caucasus. Alexander, after building an Alexandria at its foot (probably at Hupian near Charikar), crossed into Bactria, first reaching Drapsaca, or Adrapsa. This has been interpreted as Anderab, in which case he probably crossed the Khawak Pass, but the identity is uncertain. The ancient Zend name is, according to Rawlinson, Paresina, the essential part of Paropamisus; this accounts for the great Asiastic Parnassus of Aristotle, and the Pho-lo-sin-a of Hsüan Tsang.
The name Hindu Kush is used by Ibn Batuta, who crossed (c. 1332) from Anderab, and he gives the explanation of the name which, however doubtful, is still popular, as (Pers.) Hindu-Killer, “because of the number of Indian slaves who perished in passing” its snows. Baber always calls the range Hindu Kush, and the way in which he speaks of it shows clearly that it was a range that was meant, not a solitary pass or peak (according to modern local use, as alleged by Elphinstone and Burnes). Probably, however, the title was confined to the section from Khawak to Koh-i-Baba. The name has by some later Oriental writers been modified into Hindu Koh (mountain), but this is factitious, and throws no more light on the origin of the title. The name seems to have become known to European geographers by the Oriental translations of the two Petis de la Croix, and was taken up by Delisle and D’Anville. Rennell and Elphinstone familiarized it. Burnes first crossed the range (1832). A British force was stationed at Bamian beyond it in 1840, with an outpost at Saighan.
The Hindu Kush, formidable as it seems, and often as it has been the limit between petty states, has hardly ever been the boundary of a considerable power. Greeks, White Huns, Samanidae of Bokhara, Ghaznevides, Mongols, Timur and Timuridae, down to Saddozais and Barakzais, have ruled both sides of this great alpine chain.