Nilotic speaking pastoralists who lived in the more arid and less fertile North were mobile and ready to resort to arms in defence of their cattle or in raids to appropriate the cattle of others. But their political organization was less, based on kinship and decisions by kin-group elders. In the meeting of cultures, they may have acquired the ideas and symbols of political chiefship from the Bantu speakers, to whom they could offer military protection, and with whose elites they sometimes joined and intermarried. It is theorized a system of patron-client relationships developed, whereby a pastoral elite emerged, entrusting the care of cattle to subjects who used the manure to improve the fertility of their increasingly overworked gardens and fields.