Claim: Ethiopia is a nation of many languages.

A federation -LRB- also known as a federal state -RRB- is a political entity characterized by a union of partially self-governing states or regions under a central -LRB- federal -RRB- government . In a federation , the self-governing status of the component states , as well as the division of power between them and the central government , is typically constitutionally entrenched and may not be altered by a unilateral decision of either party , the states or the federal political body . Alternatively , federation is a form of government in which sovereign power is formally divided between a central authority and a number of constituent regions so that each region retains some degree of control over its internal affairs .   The governmental or constitutional structure found in a federation is known as federalism . It can be considered the opposite of another system , the unitary state . Germany , with 16 Bundesländer , is an example of a federation , whereas neighboring Austria and its Bundesländer was a unitary state with administrative divisions that became federated , and neighboring France , by contrast , has always been unitary .   Federations are often multiethnic and cover a large area of territory -LRB- such as Russia , the United States , India , or Brazil -RRB- , but neither is necessarily the case . The initial agreements create a stability that encourages other common interests , reduces differences between the disparate territories , and gives them all even more common ground . At some time , that is recognized and a movement is organized to merge more closely . At other times , especially when common cultural factors are at play such as ethnicity and language , some of the steps in this pattern are expedited and compressed .   Several ancient chiefdoms and kingdoms , such as the 4th-century BC League of Corinth , Noricum in Central Europe , and the Haudenosaunee Confederation in pre-Columbian North America , could be described as federations or confederations . The Old Swiss Confederacy was an early example of formal non-unitary statehood .   Several colonies and dominions in the New World consisted of autonomous provinces , transformed to federal states upon independence -LRB- see Spanish American wars of independence -RRB- . The oldest continuous federation , and a role model for many subsequent federations , is the United States . Some of the New World federations failed ; the Federal Republic of Central America broke up into independent states ten years after its founding . Others , such as Argentina and Mexico , have shifted between federal , confederal , and unitary systems , before settling into federalism . Brazil became a federation only after the fall of the monarchy -LRB- see States of Brazil -RRB- , and Venezuela became a federation after the Federal War . Australia and Canada are also federations .   Germany is another nation-state that has switched between confederal , federal and unitary rules , since the German Confederation was founded in 1815 . The North German Confederation , the succeeding German Empire and the Weimar Republic were federations .   Founded in 1922 , the Soviet Union was formally a federation of Soviet Republics , Autonomous republics of the Soviet Union and other federal subjects , though in practice highly centralized under the Government of the Soviet Union . The Russian Federation has inherited a similar system .   Nigeria , Pakistan , India and Malaysia became federations on or shortly before becoming independent from the British Empire .   In some recent cases , federations have been instituted as a measure to handle ethnic conflict within a state , such as Bosnia and Herzegovina , and Iraq since 2005 .