of the first sedentary villages. Before expanding into a fully developed empire, the Ubaid culture had the domestication of animals and plants such as: wheat, barley, lentils, sheep, goats, and cattle. Additionally, they developed an irrigation system to better serve their agricultural needs, which is further developed on a larger scale in civilizations and expand it beyond agricultural purposes. Chiefdoms Chiefdoms are stratified societies that characteristically have a two-tier settlement pattern, with a central town for administrative and religious duties surrounded by satellite farming villages. They are distinguished from tribes by hereditary inequality between those born into the chiefly class and those born as commoners. The chief and his or her relatives are also often considered divine. Chiefdoms may arise out of necessity under external threat. Villages might join under a leader who is believed to deliver followers from harm, and in the process the leader may become deified. Once a chiefdom is formed, adjacent communities have few choices except to join the chiefdom, leave the region, or form a rival chiefdom. States States are stratified societies that are more complex than chiefdoms. States often have a three-tier settlement pattern consisting of cities, towns and farming villages. Cities are surrounded by towns that are headed by minor administrators who interact on behalf of the elites with the neighboring villages. Writing first developed in states as a way to organize tax collection, public work and military service. Factors There are four core components that enabled the creation and development of an organized power structure. The concept of a complex society and modern state was born from a need for cohesive organization and for protection from external threats. The emergence of a civilized or complex society is derived from agricultural developments, necessary division of labor, a hierarchical political structure, and the development of institutions as tools for control. Collectively, they create the conditions for a society of complex nature where a new kind of relationship between people emerges. The relationship that emerges is a dependency between one group providing wealth and food and the other who governs and provides protection. Agricultural development The transition from agrarian, nomadic individuals to industrial and sedentary habits emerged from the improvements made in agricultural and central food planning. Early sedentary societies have been argued to emerge as early as 1600 BCE along southern Mexico, as there is a correlation between domesticated plant production, sedentism and pottery