RICHARD FLETCHER was one of the outstanding talents in English and Spanish medieval scholarship. When he died at his desk he was still engaged on his most ambitious project, a monumental study of the fall of the Roman Empire.

Whether he might have come to be remembered as the Edward Gibbon de nos jours we will never know, but such a comparison was made not long ago by no less an authority than the historian Raymond Carr. It was not a comparison Fletcher himself would have invited. Although he shared his 18th-century predecessor’s disrespect for those in authority, he would have recoiled from the thought of being a cosmopolitan intellectual almost as much as from the fate of being a television history don.

At the heart of his qualities as a man and historian was his unswerving loyalty to his own home and place, that place being not so much the city of York, where he taught for nearly all his career, as the Yorkshire countryside. And he approached the personalities of the past with a wry concern and sense of mischief which owed more to his solitary walks in the country than to the seminar rooms and conferences (which he disliked) of the modern university.

Born in 1944, Richard Fletcher spent his childhood at Wighill near Tadcaster. The village was probably the site of the notorious murder of Earl Uthred of Northumbria in 1016, and the 14-year old future historian began to examine the evidence for that story of “murder and revenge in Anglo-Saxon history” which he finally told in his last book, Bloodfeud (2002).

While at Harrow (1957-62) the precocious schoolboy consulted the 1786 edition of Domesday Book in the school library to decipher the entry for the manor of Wighill, thereby, he said, “'taking my first steps on a ladder whose rungs I am still climbing”.

Of his time at Harrow Fletcher said little except to argue that five years at an English public school were an ideal apprenticeship for an aspirant historian by introducing him at close quarters to some of the wilder extravagances of human behaviour.

He went with a history scholarship to Worcester College, Oxford, from 1962 to 1965. There he had the good fortune to be taught by James Campbell, the university’s most benevolently influential early medieval-history tutor. After his BA he embarked on a DPhil thesis in medieval Spanish history which became his first major book, The Episcopate in the Kingdom of León in the Twelfth Century (1978).

So original a venture into such uncharted territory that its implications have yet to be properly developed, this monograph is also a tribute to the assiduity of Fletcher’s conducted viaje de investigación around 20 of Iberia’s notoriously inaccessible cathedral archives.

As for the bishops of León themselves, in a characteristic judgment Fletcher concluded that they “were rather a dim lot whose dimness was not altogether their own fault”.

In 1969 he was appointed to a lectureship at the University of York. He made an immediate and enduring impact on his students and colleagues. The latter were not a little envious to discover that their new colleague often found the time to drive down to the Royal Station Hotel for a morning shave. Although Fletcher was not a dandy, his sartorial tastes — especially his collection of corduroy trousers — attracted much admiring comment, to which his invariable response was that he “chose his shoes and clothes, like his friends and historical enthusiasms, to last”.

He became an increasingly assured master of the memorable historical judgment. His Saint James’s Catapult: The Life and Times of Diego Gelmírez of Santiago de Compostela (1984) exemplified his ability to create an exciting detective story from apparently intractable source material.

The Quest for El Cid (1989), later translated into Spanish and Italian, made him a figure of international standing as well as the winner of the Wolfson Literary Award for History and (to his especial delight) the Los Angeles Times Book Prize. Three years later, Moorish Spain (1992) immediately became — as it still is — the ideal historical companion for travellers to Andalucia.

By this stage of his career Fletcher’s intellectual horizons were no longer confined to medieval Spain and Anglo-Saxon England; and in 1997 there appeared his longest and most remarkable work, The Conversion of Europe: From Paganism to Christianity 371-1386.

Greeted with enthusiasm on both sides of the Atlantic (“an enthralling book of real genius,” according to the late Archbishop Robert Runcie), in many ways The Conversion of Europe has no real precedent in English historical literature.

In a relaxed, discursive, almost conversational style, Fletcher reflected perceptively on the tortuous course of the most significant theme in the history of Europe, its conversion to Christianity between the age of Constantine the Great and the year (1385) when the coronation of Ladislas as King of Poland made medieval Latin Christendom “at last formally complete”.

For Fletcher the most important result of the outstanding success of The Conversion of Europe was to persuade him to spend the remainder of his life responding to similarly immense challenges. He was appointed to a professorship at York in 1998, but he had become disenchanted with the increasing intrusion of managerial and inquisitorial influences into the university world. In 2001 he retired from the university, thereafter living, in his own words, “disburdened and carefree ”.

Not entirely carefree, one need hardly add. The World of El Cid (2000), an invaluable edition of the four principal chronicles of the Spanish Reconquista, published in collaboration with Professor Simon Barton, had proved that his formidable powers of minute textual analysis were undimmed.

Fletcher would no doubt have gone on to write many other penetrating and entertaining books, so perhaps there is at least the consolation that in some ways he wrote his own most fitting epitaph.

In the elegiac final paragraphs of The Conversion of Europe, he meditated on the mysterious way in which, a mile above his parish church of St Gregory’s Minster at Kirkdale — where he is buried — the little Hodge Beck plunges underground only to re-emerge down the valley as unpredictably as it had earlier disappeared.

In an image worthy of his greatest master, the Venerable Bede, Fletcher invited his readers to consider the thought that the conversion of Europe to Christianity, the progress of so-called “history” and even the enigma of human life itself are as inexplicable but as “numinous and sacred” as the course of that little Yorkshire stream.

Fletcher is survived by his wife, Rachel Toynbee, whom he married in 1976, and by their son and two daughters.

Richard Fletcher, medieval historian, was born on March 28, 1944. He died of a heart attack on February 28, 2005, aged 60.