to the river Maulé in the south of Chile. Thus the empire was more than 2000 miles in length, from the river Maulé to Pasto.
From that time the Collas and Chilians furnished valuable contingents to the Inca armies.
The Inca Tupac Yupanqui saw the necessity for establishing permanent tranquillity in the Collao by a system of colonisation. Great numbers of Collas and Lupacas were sent to colonise the charming valleys of Arequipa, Moquegua, and Tacna on the west side of the maritime cordillera. Others were sent down into the Amazonian valleys to the eastward, to cultivate coca and wash for gold. Traditions are preserved even now, which tell from which district in the Collao the exiles were taken, and whither sent. The conquest of the Collao was of immense importance, because it was the only source of tin for their bronze weapons and tools, and the principal source of gold from Caravaya.
Tupac Inca was deeply impressed by the vast ruins at Tiahuanacu, of unknown origin, by the beauties of the great lake, and of the sun rising over the snowy peaks of Illimani and Illampu. He caused a palace to be built on the island of Coati, in the lake, with baths and gardens. A number of Orejones remained in the Collao to carry on the administration, and emigrants arrived to take the places of the exiled Collas and Lupacas.
These emigrants were chiefly Quichuas of various tribes from Cunti-suyu. A number of Aymaras, from the head-waters of the Pachachaca,
