270 BETWEEN HASTINGS AND CORNWALLIS

the only substantial obstacle to their rising ascendency, lay always, then as now, in the possibility of some for- eign invasion by the army of some rival power led by a chief at the head of the fighting tribes of Central Asia. But the Sikhs were making it impossible for any such Asiatic army to penetrate into the heart of the Panjab without encountering the obstinate resist- ance of men united to defend their faith and their fatherland, in a spirit very unfamiliar to the quiescence of ordinary Hinduism. The kingdom founded by Ahmad Shah had extended, from its citadel in the Afghan mountains, on the west over Khorasan, and on the east over the Upper Panjab. It had thus been built up by wresting one frontier province from Persia and the other from India, and as the Afghan ruler was cordially detested in both these countries, whenever he was engaged by invasion or revolt on one flank, the opportunity was sure to be taken by his enemies on the other. Even Ahmad Shah failed to hold such a position without great exertions, and after his death it became quite untenable. Twenty years later Zaman Shah, a very able Afghan king, was obliged to retire from Lahore. This last abortive expe- dition closed the long series of irruptions by the Mo- hammedan conquerors, who for seven hundred years had swept down from the north upon the plains of India, and had founded dynasties which were only sus- tained by constant recruitment from their native coun- tries beyond the mountains. Thenceforward the Sikhs were not only able to hold the line of the Indus Eiver