FACE PAGE 1. General Orographic Map of Afghanistan and Baluchistan, showing Arab trade routes (see page 190 _et seq._) _With Introduction_ 2. Sketch of Alexander's Route through the Kabul Valley to India 94 3. Greek Retreat from India (_Journal of the Society of Arts_, April 1901) 135 4. The Gates of Makran (_Journal of the Royal Geographical Society_, April 1906) 284 5. Sketch of the Hindu Kush Passes 500 [Illustration: OROGRAPHICAL MAP OF AFGHANISTAN & BALUCHISTAN COMPILED BY SIR THOMAS H. HOLDICH, K.C.M.G., K.C.I.E., C.B.] INTRODUCTION Since the gates of India have become water gates and the way to India has been the way of the sea, very little has been known of those other landward gates which lie to the north and west of the peninsula, through which have poured immigrants from Asia and conquerors from the West from time immemorial. It has taken England a long time to rediscover them, and she is even now doubtful about their strategic value and the possibility of keeping them closed and barred. It is only by an examination of the historical records which concern them, and the geographical conditions which surround them, that any clear appreciation of their value can be attained; and it is only within the last century that such examinations have been rendered possible by the enterprise and activity of a race of explorers (official and otherwise) who have risked their lives in the dangerous field of the Indian trans-frontier. In ancient days the very first (and sometimes the last) thing that was learned about India was the way thither from the North. In our times the process has been reversed, and we seek for information with our backs to the South. We have worked our way northward, having entered India by the southern water gates, and as we have from time to time struggled rather to remain content within narrow borders than to push outward and forward, the drift to the north has been very slow, and there has never been, right from the very beginning, any strenuous haste in the expansion of commercial interests, or any spirit of crusade in the advance of Conquest.