He then studied at Christ Church, Oxford, where he was elected Gladstone Research Exhibitioner in 1941. Carr was briefly a lecturer at University College, London, in 1945–1946, before returning to Oxford as a Fellow of All Souls College, 1946–1953. He was next a Fellow of New College, 1953–1964, then Director of Oxford's Latin American Centre, 1964–1968 and the University's Professor of the History of Latin America, 1967–68. He became a Fellow of St Antony's College, Oxford, in 1964, Sub-Warden of the college in 1966 and Warden in 1968, a position he held until his retirement in 1987. After his retirement from Oxford, he was King Juan Carlos Professor of Spanish History at New York University in 1992. Carr's successor as Warden of St Antony's, Ralf Dahrendorf, has described Carr's tenure of the post as the College's 'Fiesta days'. As a historian and Hispanist, Carr's main interest lay in the vicissitudes of 19th and 20th century Spain, and he was also a specialist in Latin American and Swedish history. In the words of Sir John Elliott, " his book on Spain between 1808 and 1939 is basic to a better understanding of the era, and the later generation of historians, both within Spain and abroad, have followed up the leads that Carr gives in his book to great benefit." His "Modern Spain, 1875-1980" was called by the "Times Literary Supplement" "a turning point in Spanish historiography - nothing comparable in scope, profundity, or perceptiveness exists." At St Antony's, he established an Iberian Centre, of which he was co-director with Joaquin Romero Maura. Paul Preston wrote in 1984 of their collaboration "Between them, Carr and Romero Maura instilled an intellectual rigour into modern Spanish historiography which had previously been conspicuously lacking." Carr also wrote an extensive foreword to the 1993 edition of "The Spanish Labyrinth" by Gerald Brenan. A Fellow of the British Academy since 1978, in 1983 he was awarded the Order of Alfonso X el Sabio by King Juan Carlos of Spain and in 1999 the Prince of Asturias Award for Social Sciences. He is considered, together with Angus Mackay and Sir John Huxtable Elliott, a major figure in developing Spanish historiography. Carr wrote for "The Spectator" in 2007 - "I am old-fashioned and aged enough to believe that the best history is the work of the lone individual."