The Piegan, Blood, and Blackfeet Indians were three allied tribes of Algonquin stock who had emerged from the northern forest and taken possession of the plains, driving their enemies, the Kootenay, Salish, and Snake Indians, before them to the mountains. Since the white men had come to trade on the river, they had advanced from the Eagle hills in western Saskatchewan to the very foot of the Rockies. This rapid conclusion of an age-long struggle for the mastery of the grazing country had been due to the fire-arms which they had procured from the traders. The manners and customs of the confederate tribes were in keeping with their war-like disposition and constant danger. Unlike the scattered forest Indians, they lived in large camps, and without yielding their traditional liberty to the control of a single authority, they had nevertheless evolved a rudimentary form of social organization. Hunters of the bison, they were in constant need of horses. Horse-stealing was thus among them an honourable pursuit, and their raids extended far to the south and west. During the winter of Thompson's stay among them, a raid on the Snakes took a part of two hundred and fifty warriors a distance of one thousand, five hundred miles to the south-west, as was testified by the thirty well-bred animals that were brought back to camp, and the Spanish saddles and bridles that lay thrown about among the tents. Of the three allied tribes, the Piegans occupied the most exposed position, and consequently led the most precarious and watchful life. From boyhood they were trained in arms, and their martial bearing and enterprising character produced a strong impression upon Thompson. They had an hereditary civil chief or "orator", as he was called, who presided at all councils except those of war. Arrayed in his splendid mantle of otter skin, he paced the camp each day three hours after sunset, reciting in a loud voice the news which his couriers had gathered, announcing in particular where the herds of bison were feeding and what direction they were taking. The war chief, on the other hand, was a self-made man, whose power and influence had developed from his conduct in war. Kootanae Appee, as he was called, was a magnificent giant, six feet six inches in height, and was the father of twenty-two warriors, no less tall and sinewy than himself. In after years, when Thompson was battling his way south along the Columbia river, the bond of friendship which he now forged with this old chief stood him in good stead.