Hugh Redwald Trevor-Roper, Baron Dacre of Glanton, FBA (15 January 1914 - 26 January 2003), was a British historian of early modern Britain and Nazi Germany. He was Regius Professor of Modern History at the University of Oxford. Trevor-Roper was made a life peer in 1979 on the recommendation of Prime Minister Margaret Thatcher, choosing the title Baron Dacre of Glanton. Trevor-Roper was a polemicist and essayist on a wide range of historical topics, but particularly England in the 16th and 17th centuries and Nazi Germany.

A notable thesis propagated by Trevor-Roper was the "general crisis of the 17th century". He argued that the middle years of the 17th century in Western Europe saw a widespread break-down in politics, economics and society caused by demographic, social, religious, economic and political problems. In this "general crisis," various events, such as the English Civil War, the Fronde in France, the climax of the Thirty Years' War in Germany, troubles in the Netherlands, and revolts against the Spanish Crown in Portugal, Naples and Catalonia, were all manifestations of the same problems. The most important causes of the "general crisis" in Trevor-Roper's opinion were conflicts between "Court" and "Country"; that is between the increasingly powerful centralizing, bureaucratic, sovereign princely states, represented by the Court, and the traditional, regional, land-based aristocracy and gentry, representing the country. In addition, he said that the religious and intellectual changes introduced by the Reformation and the Renaissance were important secondary causes of the "general crisis." The "general crisis" thesis generated controversy between supporters of this theory, and those, such as the Marxist historian Eric Hobsbawm, who agreed with him that there was a "general crisis," but saw the problems of 17th century Europe as more economic in origin than Trevor-Roper would allow. A third faction denied that there was any "general crisis," for example the Dutch historian Ivo Schoffer, the Danish historian Niels Steengsgaard, and the Soviet historian A. D. Lublinskaya. Trevor-Roper's "general crisis" thesis provoked much discussion, and led experts in 17th century history such as Roland Mousnier, J. H. Elliott, Lawrence Stone, E. H. Kossmann, Eric Hobsbawm and J. H. Hexter to become advocates of the pros and cons of the theory. At times the discussion became quite heated; the Italian Marxist historian Rosario Villari, speaking of the work of Trevor-Roper and Mousnier, claimed that: "The hypothesis of imbalance between bureaucratic expansion and the needs of the state is too vague to be plausible, and rests on inflated rhetoric, typical of a certain type of political conservative, rather than on effective analysis." Villari accused Trevor-Roper of downgrading the importance of what Villari called the English Revolution (the usual Marxist term for the English Civil War), and insisted that the "general crisis" was part of a Europe-wide revolutionary movement. Another Marxist critic of Trevor-Roper the Soviet historian A. D. Lublinskaya attacked the concept of a conflict between "Court" and "Country" as fiction, arguing there was no "general crisis;" instead she maintained that the so-called "general crisis" was merely the emergence of capitalism.

What was the crisis?
a widespread break-down in politics, economics and society caused by demographic, social, religious, economic and political problems.