A curious feature is that as there are castes for all trades, so there are hereditary thief castes. Hired watchmen generally belong to these castes on a principle which is obvious. The mountaineers of Central India are a different race from the dwellers in the plain. They appear to have been aboriginal inhabitants before the Hindu invasion. The mountaineers of the Himalayas are in race more akin to the Chinese. Established Hindu chronology is found in the line of Magadha. We can fix the King Ajata Satru, who ruled, in the time of Gotama, in the middle of the sixth century B.C. Some generations later comes Chandragupta--undoubtedly the Sandracottus of Diodorus. The early legend apparently begins to give place to real history with Rama, who certainly invaded the Deckan. He would seem to have been a king in Oudh. The next important event is the war of the Maha Bharata, probably in the fourteenth century B.C. Soon after the main seat of Government seems to have transferred to Delhi. The kingdom of Magadha next assumes a commanding position though its rulers long before Chandragupta were of low caste. Of these kings the greatest is Asoka, three generations after Chandragupta. There was certainly no lord paramount of India at the time of Alexander's invasion. Nothing points to any effective universal Hindu Empire, though such an empire is claimed for various kings at intervals until the beginning of the Mahometan invasions. _II.--The Mahometan Conquest_ The wave of Mahometan conquest was, in course of time, to sweep into India. By the end of the seventh century the Arabs were forcing their way to Cabul 664 A.D. At the beginning of the next century Sindh was overrun and Multan was captured; nevertheless, no extended conquest was as yet attempted. After the reign of the Calif Harun al Raschid at Bagdad the Eastern rulers fell upon evil days. Towards the end of the tenth century a satrapy was established at Ghazni and in the year 1001 Mahmud of Ghazni, having declared his independence, began his series of invasions. On his fourth expedition Mahmud met with a determined resistance from a confederacy of Hindu princes. A desperate battle was fought and won by him near Peshawer. Mahmud made twelve expeditions into India altogether, on one of which he carried off the famous gates of Somnat; but he was content to leave subordinate governors in the Punjab and at Guzerat and never sought to organise an empire. During his life Mahmud was incomparably the greatest ruler in Asia.