The noun "commonwealth", meaning "public welfare general good or advantage" dates from the 15th century. Originally a phrase (the common-wealth or the common weal - echoed in the modern synonym "public weal") it comes from the old meaning of "wealth", which is "well-being", and is itself a loose translation of the Latin res publica (republic). The term literally meant "common well-being". In the 17th century, the definition of "commonwealth" expanded from its original sense of "public welfare" or "commonweal" to mean "a state in which the supreme power is vested in the people; a republic or democratic state". "Better things were done, and better managed ... under a Commonwealth than under a King." Pepys, Diary (1667)
The term evolved to become a title to a number of political entities. Three countries - Australia, the Bahamas, and Dominica - have the official title "Commonwealth", as do four U.S. states and two U.S. territories. More recently, the term has been used to name some fraternal associations of nations, most notably the Commonwealth of Nations, an organization primarily of former territories of the British Empire, which is often referred to as simply "the Commonwealth".
Translations of Roman writers' works to English have on occasion translated "Res publica", and variants thereof, to "the commonwealth", a term referring to the Roman state as a whole.
The Commonwealth of England was the official name of the political unit (de facto military rule in the name of parliamentary supremacy) that replaced the Kingdom of England (after the English Civil War) from 1649-53 and 1659-60, under the rule of Oliver Cromwell and his son and successor Richard. From 1653 to 1659, although still legally known as a Commonwealth, the republic, united with the former Kingdom of Scotland, operated under different institutions (at times as a de facto monarchy) and is known by historians as the Protectorate. In a British context, it is sometimes referred to as the "Old Commonwealth".
The Icelandic Commonwealth or the Icelandic Free State (Icelandic: Þjóðveldið) was the state existing in Iceland between the establishment of the Althing in 930 and the pledge of fealty to the Norwegian king in 1262. It was initially established by a public consisting largely of recent immigrants from Norway who had fled the unification of that country under King Harald Fairhair.
Republic is still an alternative translation of the traditional name of the Polish-Lithuanian Commonwealth. Wincenty Kad?ubek (Vincent Kadlubo, 1160-1223) used for the first time the original Latin term res publica in the context of Poland in his "Chronicles of the Kings and Princes of Poland". The name was used officially for the confederal country formed by Poland and Lithuania 1569-1795.
It is also often referred as "Nobles' Commonwealth" (1505-1795, i.e., before the union). In the contemporary political doctrine of the Polish-Lithuanian Commonwealth, "our state is a Republic (or Commonwealth) under the presidency of the King". The Commonwealth introduced a doctrine of religious tolerance called Warsaw Confederation, had its own parliament Sejm (although elections were restricted to nobility and elected kings, who were bound to certain contracts Pacta conventa from the beginning of the reign).
"A commonwealth of good counsaile" was the title of the 1607 English translation of the work of Wawrzyniec Grzyma?a Go?licki "De optimo senatore" that presented to English readers many of the ideas present in the political system of the Polish-Lithuanian Commonwealth.
Between 1914 and 1925, Catalonia was an autonomous region of Spain. Its government during that time was given the title mancomunidad (Catalan: mancomunitat), which is translated into English as "commonwealth". The Commonwealth of Catalonia had limited powers and was formed as a federation of the four Catalan provinces. A number of Catalan-language institutions were created during its existence.
Between 1838 and 1847, Liberia was officially known as the "Commonwealth of Liberia". It changed its name to the "Republic of Liberia" when it declared independence (and adopted a new constitution) in 1847.
"Commonwealth" was first proposed as a term for a federation of the six Australian crown colonies at the 1891 constitutional convention in Sydney. Its adoption was initially controversial, as it was associated by some with the republicanism of Oliver Cromwell (see above), but it was retained in all subsequent drafts of the constitution. The term was finally incorporated into law in the Commonwealth of Australia Constitution Act 1901, which established the federation. Australia operates under a federal system, in which power is divided between the federal (national) government and the state governments (the successors of the six colonies). So, in an Australian context, the term "Commonwealth" (capitalized) refers to the federal government, and "Commonwealth of Australia" is the official name of the country.
The Bahamas uses the official style Commonwealth of The Bahamas.
The term "commonwealth" has one of two political meanings within the United States:
Four states in the United States officially designate themselves as "commonwealths". All four were original colonies or parts thereof (Kentucky was originally a part of the land grant of the Colony of Virginia) and share a strong influence of colonial common law in some of their laws and institutions. The four are:
"Commonwealth" is also used in the United States to describe the political relationship between the United States and the overseas unincorporated territories:
The Commonwealth of Nations--formerly the British Commonwealth--is a voluntary association or confederation of 52 independent sovereign states, most of which were once part of the British Empire. The Commonwealth's membership includes both republics and monarchies. The head of the Commonwealth of Nations is Queen Elizabeth II, who reigns as monarch directly in 16 member states known as Commonwealth realms.
The Commonwealth of Independent States (CIS) is a loose alliance or confederation consisting of 10 of the 15 former Soviet Republics, the exceptions being Turkmenistan (a CIS associate member), Lithuania, Latvia, Estonia, and Georgia. Georgia left the CIS in August 2008 after a clash with Russia over South Ossetia. Its creation signalled the dissolution of the Soviet Union, its purpose being to "allow a civilised divorce" between the Soviet Republics. The CIS has developed as a forum by which the member-states can co-operate in economics, defence, and foreign policy.