As the early states and empires grew in number, size, and population, they frequently competed for resources and came into conflict with one another. In quest of land, wealth, and security, some empires expanded dramatically. As these empires expanded their boundaries, they also faced the need to develop policies and procedures to govern their relationships with ethnically and culturally diverse populations: sometimes to integrate them within an imperial society and sometimes to exclude them. By expanding their boundaries too far, they created political, cultural, and administrative difficulties that they could not manage. They also experienced environmental, social, and economic problems when they over exploited their lands and subjects and permitted excessive wealth to be concentrated in the hands of privileged classes.