Hugh Thomas, who has died aged 85,was a historian with an enduring interest in and passion for the Hispanic world straddling epochs, continents and empires. He also played an active part as a policy adviser to Margaret Thatcher, and in his later years served in the House of Lords as a life peer, never seeing this as place of  patronage  let alone retirement but as an integral part of an effective and accountable  parliamentary democracy.

He had developed an interest in Spain after a first visit in the 1950’s when  he set himself the task of writing the  first comprehensive  history of the Spanish Civil War. The result was a ground-breaking account, detailed and innovative in its research, highly readable, and above all balanced in a way that contrasted with the poorly sourced, prejudiced  and often crudely  propagandist   accounts that had emerged until then  from each side of the conflict , both in  Spain and the UK.

An international best-seller, the seminal The Spanish Civil War  set a hard to beat high standard for other researchers to surpass while encouraging  an increasingly prolific bibliography and evolving academic  courses on the subject.

Several of Thomas’s subsequent works of history  came to be characterised by a  similar  sense of perspective and literary power unrivalled by any other academics in his field, although his ventures into fiction proved less successful. He didn’t easily suffer historians  he considered unworthy competitors, but was generous in his moral support for much lesser known and underpaid  younger writers he respected.

Thomas was a true liberal, in his openness to and willingness  to engage with  alternative views, while unyielding in core principles , and never  succumbing to those on the extreme of the political spectrum.

He showed little patience with fellow historians whose subjectivity distorted and manipulated the material they had accessed to justify their opinions. For example he took issue with the description   of the Spanish Empire as cruel and rapacious by the  Victorian Cambridge professor JR Seeley  in his account of the British  Empire . Thomas wrote that such an assessment made Seeley appear “ an ignorant and parochial ideologue.”

Thomas’s comment is to be found in World Without End (2014) , the third volume of his magnificent trilogy about the Spanish Empire published over the last fourteen years and which stand as a worthy bookend to his life as a historian.

Even  in his advancing years, Thomas never  shied away from the challenge of another ‘magnus opus’ while along the way writing novels and periodically delving into smaller scale  projects like his biography of Pierre-Augustin Caron de Beaumarchais, the 18^th century French polymath.

Thomas was born into a comfortable middle-class family in Windsor in 1931-his father was a colonial commissioner- and  was educated at one of Britan’s leading private boarding schools Sherborne . In  1953 he graduated from  Cambridge  where the  wit and intellectual sharpness  that stuck with him for most of his life , had him elected president of the Cambridge Union before he pursued further studies at the Sorbonne.

Thomas’s firs employment was at  the Foreign Office, where he worked for two years in a department dealing with the United Nations,  and was briefly a prospective Labour candidate. He was  Professor of  History  at Reading University from 1966-1975. By then several years had gone since he had approached for the first time my parents the late Tom Burns and Mabel Marañón  at their home in London. My father had developed a life-time interest in Spain after serving in the British  embassy in Madrid during World War 2 and marrying  my Spanish mother, the youngest daughter of Gregorio Marañón a Spanish physician, scientist, historian, philosopher, humanist, and writer, considered one of the most brilliant Spanish intellectuals of the 20th century. My parents  provided Thomas with an invaluable list of contacts straddling the Spanish political  spectrum, from Franco ministers  to former members of the Republican government who had fled to exile, among many others. Thereafter, Thomas pursued his research  into the Spanish Civil War, and developed an enduring friendship with the Burns Mabel Marañón  family, along with other members of the BritishSpanish community based in London grouped in cultural organizations  like the British Spanish Society.

I count myself honored to have benefited in my early days as a writer from Thomas’s generosity, as he  offered me invaluable confidential advice linked to  separate books I wrote on the Falklands War (The Land that Lost its  Heroes) and on British intelligence in Wartime Spain-(Papa Spy) apart from becoming an enduring point of reference on all matters relating to British-Spanish relations.

After his Spanish Civil War book,  Thomas followed up  with another large volume, this time  on the history of Cuba, which took a critical view of Castro’s submission  to Soviet influence and his curbing of human rights. By the time of its publication  in the mid 1970’s Thomas’s political allegiances had shifted away from the Labour party to the Conservative Party  because of what he saw as Labour’s  less than enthusiastic   attitude to Britain’s membership of the European Common Market.

After Mrs Thatcher came to power in 1979, Thomas developed a personal friendship as well as an advisory role  , heading up the centre-right think-tank  Center For Policy Studies. He was then honored as  Lord Thomas of Swynnerton  of Notting Hill, the London neighborhood where he lived .

Thomas allowed some years to elapse before sharing details of the  interesting part he played in trying to win over some of the so-called  Notting Hill ‘ set’ to the Thatcher ‘revolution’ at a private dinner he organized  in his large  Georgian House in Ladbroke Grove with her as the guest of honor.

It was late 1982, a few months   after the British victory in the  Falklands War when despite her  popularity among a majority of voters, Thatcher had yet to win hearts and minds ,among her enduring enemies,  not least  certain writers,  and academics. Thomas was seen as a potential bridge between  Number 10 and their world . By then he knew Thatcher well because he ran her favourite thinktank, the Centre for Policy Studies.

Those invited to the  dinner with Thatcher at Thomas’s house  included the poets Stephen Spender and Philip Larkin, , hispanist writer VS Pritchett, the  writer Anthony Powell, the playwright Tom Stoppard,   and the Peruvian novelist Mario Vargas Llosa, who had taught Hispanic studies  at King’s College London and was pursuing his international literary and political  career.

The meal was cooked by the artist Lady Thomas (formally Vanessa Jebb, the daughter of Gladwyn Jebb, first acting secretary-general of the United Nations), with their daughter Bella and one of her friends, Maggie Evans, acting as waitresses. The guests dined on pheasant and drank Rioja, a wine that at the time had yet to enter the British supermarket shelves on a major scale.

The Thomas’s were  always convivial hosts, and Vanessa’s home cooking delicious, as I can attest having attended  one such ‘intellectual’ dinner with the late Harold Pinter and his wife Antonia  Fraser some five years later after I was awarded the Somerset Maugham  prize for my book on  the Falklands war, a similar prize given to Thomas after he  published the first edition of the  Spanish Civil War in 1962. By then   it was evident that any attempt to reconcile Thatcher’s personality and politics with the liberal tendencies of  the north London  literati was doomed to failure.

Thomas’s politics were individualistic, radical, and pragmatic-very English  traits according to his Spanish admirers who read his books and articles in translation with huge interest and who have  produced an outpouring of generous obituaries on the news of his death.

As I came to know him, Thomas was outspoken when he felt it necessary to the point of brashness, and enjoyed flattery, while never allowing himself  to be seduced by power or pigeonholed  by ideology.

In 1997 he quit what he saw as the  increasing  anti-Europeanism in the Conservative  Party and  joined the Liberal Democrats. He later became  a cross-bencher in  the House of Lords rather than openly support any one party.

Like  many of his compatriots who voted to remain in the European Union, he  was deeply shocked by the result of the British  referendum and the government’s subsequent push for Brexit. Sadly, the referendum coincided with  a period of declining health that had left Thomas increasingly  fragile and with less energy to take on big challenges as in the past.

His love of Spain and Latin America  endured however, and just months before he died made the effort to attend the inauguration  of the new offices of the Institute  of Cervantes  in London, where he conversed,  with the Spanish and Cuban ambassadors, among other friends and contacts, handing out copies of one of his books.

His committed Europeanism , as expressed through his love of Spain,  was not only political but also cultural as he made clear in an interview he gave just over a year ago to Luis Ventoso of the Spanish newspaper ABC. “ I have always strongly defended Spain, I have done everything I can in this respect. “

On Gibraltar  he was aware of the potential minefield he was treading but never shied away from his firmly held view that the best  possible future for all sides involved, if negotiated skillfully,  was shared sovereignty.

Thomas received several honors  in the UK, France, Latin America, and Spain,   including the  prestigious Spanish orders Isabel la Católica y Alfonso X el Sabio- testament to the cultural bridges he helped build in defiance of the forces of intolerance  and division.

He is survived by his wife Vanessa, and their three children Inigo, Isambad, and Bella.