The internal frontiers of the sultanate means the hinterland of garrison town.This land is between the Ganga and Yamuna.During the rule of Alauddin Khalji and Muhammad Tughluq the first set of campaigns were along this internal frontiers. During these campaigns the forest were cleared,hunter gatherers were expelled from their place and the land was given to the peasants and merchants. New fortresses and towns were established.Trade roots were protected and agriculture was promoted. The The external frontiers of the sultanate means the regions that are beyond the sultanate and are unconquered.This land was of south india. Military campaigns were held along the external frontiers and the Sultanate armies carried away precious metals and wealth.