Their protection and their connection to one of the resident foreign merchants who saw the link between them and the local merchants, who were called intermediaries and commercial agents. The large foreign trading houses with vested interests in Sudan had resident representatives to manage their affairs, such as the famous Quraish brothers, who had a resident representative in Timbuktu. Foreign merchants, and foreign communities in general, lived separately in their own quarters in the city, and were headed by one of their merchants, the eldest of the resident merchants in age. His duties included advising newcomers, and he had a seat in the city council to represent the point of view of the community. Foreigners generally praised the honesty, truthfulness, and piety of the Sudanese. Due to the strong interest of the authorities in foreign trade, they were keen on the integrity of the administration, securing the roads, and the existence of a fair system of weights and measures. As for revenues, land tax was the basis of the financial system, and customs duties were imposed on imports, not on the farmer. In Kano, the Sudanese did not impose a land tax, but rather each head of a family had to pay one hundred kurdi. In other places, the tax was imposed on tools, such as fifty kurdi on a cow. There were other taxes in Kano and Birnin Kebbi: one hundred kurdi on a measure of indigo, sixty kurdi on each slave, small taxes on goods sold in the markets, etc. There was also a system for registering fees and duties imposed on trade goods. In the city of Biskra, the land tax did not represent a burden on the inhabitants, but rather it intensified in some regions and cities, and in some districts, which forced people to leave their homes. The military organization did not differ much from that used in Sudan.