Client state refers to the notion of one state being subservient to another. This can occur in many varying ways, most commonly by treaty, military occupation, and/or economic dependence. Client states have existed for millenia as stronger powers made subservient those around them as they grew. In ancient times states such as Persia and Greek Polis' would create client states by making the personal leaders of that state subservient. One of the most prolific users of client states was Republican Rome which, instead of conquering and then absorbing into an empire, instead chose to make client states out of those it defeated, a policy which was continued up until the 1st Century BC when Imperial Power took over. The use of client states continued through the Middle Ages as the feudal system began to take hold, and in a way the entire society was based upon various divisions of a realm being clients to middle level nobility, who in turn were client to the powerful nobility, who were in turn client to the monarch, who, in the case of Catholic states, was often a client of the Pope. A treaty is a binding agreement under international law concluded by subjects of international law, namely states and international organizations. ... Belligerent military occupation, occurs when one nations military garrisons occupy all or part of the territory of another nation or recognized belligerent during an invasion (during or after a war). ... The Persian Empire is the name used to refer to a number of historic dynasties that have ruled the country of Persia (Iran). ... Ancient Greece is the term used to describe the Greek-speaking world in ancient times. ... See also Roman Republic (18th century) and Roman Republic (19th century) The Roman Republic (Latin: Res Publica Romanorum) was the republican government of the city of Rome and its territories from 510 BC until the establishment of the Roman Empire, which sometimes placed at 44 BC the year of Caesar... (2nd century BC - 1st century BC - 1st century - other centuries) The 1st century BC starts on January 1, 100 BC and ends on December 31, 1 BC. An alternative name for this century is the last century BC. (2nd millennium BC - 1st millennium BC - 1st millennium) // Events The Roman Republic... The Roman Empire is the term conventionally used to describe the Ancient Roman polity in the centuries following its reorganization under the leadership of Octavian (better known as Caesar Augustus). ... The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times, beginning with the Renaissance. ... Feudalism comes from the Late Latin word feudum, itself borrowed from a Germanic root *fehu, a commonly used term in the Middle Ages which means fief, or land held under certain obligations by feodati. ... The Lords and Barons prove their Nobility by hanging their Banners and exposing their Coats-of-arms at the Windows of the Lodge of the Heralds. ... A monarch is a type of ruler or head of state, whos titles and ascention are inherited, not earned, and represents a larger monarchical system which has established rules and customs regarding succession, duties, and powers. ... The Pope is the Catholic Bishop and patriarch of Rome, and head of the Roman Catholic Church. ...

In modern times, client states have developed based upon imperial possessions of the great European powers of 19th Century. These client states were especially obvious during the Cold War as almost the entire world divided based upon being a client state of either the Soviet Union or the United States. Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... For the generic term for a high-tension rivalry between countries, see cold war (war). ...