Twenty Years After Twenty Years After Twenty Years After () is a novel by Alexandre Dumas, first serialized from January to August 1845. A book of "The d'Artagnan Romances", it is a sequel to "The Three Musketeers" and precedes "The Vicomte de Bragelonne" (which includes the sub-plot "Man in the Iron Mask"). The novel follows events in France during the Fronde, during the childhood reign of Louis XIV, and in England near the end of the English Civil War, leading up to the victory of Oliver Cromwell and the execution of King Charles I. Through the words of the main characters, particularly Athos,
The Twenty Years' Crisis be acknowledged as a starting point. He concludes his discussion by suggesting that "elegant superstructures" such as the League of Nations "must wait until some progress has been made in digging the foundations". Since its publication, "The Twenty Years' Crisis" has been an essential book in the study of international relations. It is still commonly read in undergraduate courses, and the book is considered "one of the founding texts of classical realism". The book has served as the inspiration for numerous other works, such as "The Eighty Years' Crisis", a book written by the International Studies Association as a survey