Political and historical designations which have been much used and have come to have special significances such as names of leagues, parties, classes, movements, and the like.
_Holy Alliance_, _Dreibund_, _Roundheads_, _Independents_, _Reformation_, _Dissenter_.
25.

Names of well-known historic epochs, periods in the history of language, and geological ages and strata.

The word "age" is not capitalized except when necessary to avoid ambiguity.
_Stone age_, _Middle Ages_, _Age of Elizabeth_, _Crusades_, _Commune (of Paris)_, _Middle English_, _Neolithic_.
26.

Names of important events.
_Hundred Years War_, _Battle of Trenton_, _Louisiana Purchase_, _Norman Conquest_.
27.

Names of specific treaties, important laws, and the like.
_Peace of Amiens_, _Edict of Nantes_, _Concordat_, _Emancipation Proclamation_, _Fourteenth Amendment_.
28.