Claude Blair: Authority on arms and armour who campaigned for the Victoria and Albert Museum in a time of crisis

Claude Blair was not only a world authority on arms and armour. He revelled in the subject, and to the end of his life travelled widely in pursuit of new understanding, but he was also a doughty fighter for causes close to his heart.

He was the keeper of metalwork in the Victoria & Albert Museum for ten years before his retirement in 1982, but afterwards continued to campaign on behalf of his subject and of the museum during its greatest crisis.

He was born in Manchester; his father worked in the clothing trade but was fond of history and encouraged his son's early interest in arms and armour. He was educated at William Hulme's Grammar School, the Second World War intervening before he could continue to university.

He served in the Royal Artillery, but while stationed in Ireland was sent with colleagues to fetch the regimental beer supply. The truck in the back of which he was riding braked sharply so that Blair's leg was caught between two beer barrels, breaking it, so that he had to be invalided out of active service. He remained in the army, however, testing small arms, becoming an excellent shot and rising to the rank of captain.

After five years at Manchester University he emerged in 1951 with a history degree, later magnified on dissertation to an MA. He spent another five years as an assistant at the Tower Armouries (later the Royal Armouries), joining the V&A as an assistant keeper in 1956. He became deputy keeper 10 years later, and keeper – head of department - in 1972.

He was indefatigable in seeking out and cataloguing interesting items. His former V&A colleague Anthony North recalled visiting a small country museum's store above a bust station and finding a box labelled "Daggers" wrapped in a newspaper of 1942. With mounting excitement he opened the box, expecting to find an unregarded treasure, and discovered a 17th century English dagger, beside it a letter, signed by Claude Blair, precisely identifying it and adding a bibliography.

It was in 1989 that he rose to the defence of his former colleagues when the biggest change to its management in the V&A's history was put in place involving the displacement of its keepers and the amalgamation of departments; nine senior members of staff were either made redundant or resigned. By founding the Save the V&A Campaign when serving members of the staff had the Official Secrets Act invoked to them, forbidding them to speak publicly, he kept the issue in the public eye. He confronted one trustee who was defending the changes, Sir Christopher Frayling, face to face on the BBC's Newsnight and repeatedly referred to him impishly as "Professor Failing", perhaps slightly diminishing the seriousness of his argument.

The then director, Elizabeth Esteve-Coll, wanted to rationalise the museum's complex management structure by dividing "scholarship and housekeeping", but it was against a background of simmering unease in which, as Linda Christmas wrote in her 1989 book Chopping Down the Cherry Trees: A Portrait of Britain in the Eighties, "keeper barons of the various departments enjoy competing with each other but not with the outside world".

However, Blair and the curators sensed an irretrievable corrosion of the scholarship that had made the museum's international reputation. "The curatorial practice at the V&A had always been to acquire all-round knowledge of the objects in every aspect," said John Mallet, keeper of ceramics at the time and one of the curators who was displaced. "By separating the curators from the objects that vital relationship was being destroyed, and Claude believed it was never restored".

Blair campaigned on other issues as well, including – through the letters page of The Independent – the moving of the Royal Armouries "to form part of a theme park in Leeds" which he saw as the beginning of the privatisation of the national heritage.

He clashed with the Royal Armouries again seven years later over the acquisition for £114,000 of a 16th century helmet said to be by the Italian master armourer Filippo Negroli. "The Armouries made a blunder," he told The Independent. "This is a very dubious item and I condemn them for not consulting widely enough".

Church monuments were a lifelong passion of his, and he made a study of the medieval monuments in Cheshire churches while still a student. Together with his friend A.V.B. "Nick" Norman, the former Royal Armourer, he founded the Church Monuments Society in 1978, serving as president for some years. He also served on the architectural advisory panel of Westminster Abbey, the Council for the Care of Churches and the Churches Conservation Trust.

He joined the Monumental Brass Society in 1946, and was a vice-president. Last year he was very excited to travel to Finland to see the 15th century brass to St Henry of Finland at Nousiainen, on which he was writing an article at the time of his death. Blair was an enthusiastic member of the Society of Antiquaries and had the rare accolade of being awarded the society's Gold Medal in 1998.

He wrote prodigiously, publishing European Armour in 1958, still the standard work. There followed more than 200 books and articles on arms and armour, other historical metalwork and monuments, and in 1998 he published his two-volume study of the British crown jewels.

He was made an OBE in 1994, given an honorary doctorate by the University of Manchester in 2004 and he became a Companion of the Royal Victorian Order (CVO) in 2005. He married his wife, Joan, in 1952, and she died in 1996. Their son John is professor of medieval history and archaeology at Oxford.

Claude Blair, historian; born Manchester 30 November 1922; Keeper, Department of Metalwork, Victoria and Albert Museum, 1972–82; FSA 1956, OBE 1994, CVO 2005; married 1952 Joan Drinkwater (died 1996; one son); died 21 February 2010.