Queen Fabiola of Belgium: Spanish aristocrat headhunted to marry King Baudouin of Belgium, to whom she was a popular consort

In the late 1950s it was decided that King Baudouin I, who had been on the Belgian throne for nine years, was lonely and needed a queen. An Irish nun from the Legion of Mary, Sister Veronica O'Brien, was sent by the future Cardinal Suenens, then auxiliary bishop of Malenes, to scour Europe for a suitable bride. The king gave two conditions: she had to be aristocratic, and like him she had to be a devout Catholic.

Sister O'Brien met the headmistress of a school in Madrid who recommended a former pupil, Fabiola de Mora y Aragon, the daughter of one of Spain's biggest landowners, who was working as a nurse, to aid her in her search. It turned out that Fabiola herself fitted the bill – Sister O'Brien described her in a letter to Suenens as "a breath of fresh air, tall, thin, well-built, good-looking and striking, bubbling with life, intelligence and energy" – and despite initial reluctance she married Baudouin, remaining his steadfast consort until his death in 1993.

Fabiola Fernanda Maria de las Victorias Antonia Adelaida Mora y Aragon was born in her family's Zurbano Palace in Madrid. Her father was the Marquess of Casa Riera, whose family had made a fortune from mining in the 19th century. She was a god-daughter of Queen Victoria Eugenie, a granddaughter of Queen Victoria. Her mother was Doña Blanca de Aragon y Carillo de Albornoz, whose family had strong links to the Spanish royal family, and in 1931, when King Alfonso was forced by the republicans into exile, Fabiola's family followed, moving between Paris and Switzerland until General Franco's victory in the Spanish Civil War allowed them to return.

Fabiola trained as a nurse, living in her own apartment but dining every night at the palace; she was thought at one time to have considered joining a holy order. Friends described her as shy and pious, and after she had rejected an aristocratic suitor as not being sufficiently serious, a Spanish magazine described her as the "girl who couldn't catch a man".

She had, indeed, resigned herself to spinsterhood until Sister Veronica came calling. She married King Baudouin in Brussels in 1960. To celebrate the marriage, Spanish bakers created a type of bread, la fabiola, which is still eaten in the country today. In Belgium, Fabiola found great popularity with the people, and was often referred to as "Queen of all Belgians"; the explorer Guido Derom named Queen Fabiola Mountains, a newly discovered range in the Antarctic, in her honour in 1961.

It was a source of great sadness, however, that the couple were unable to produce an heir. Fabiola became pregnant five times but suffered a series of miscarriages and one stillbirth. "You know, I myself lost five children," she said. "You learn something from that experience. I had problems with all my pregnancies, but you know, in the end I think life is beautiful."

Given Belgium's status as a nation divided between the Francophone Walloons in the south and the Dutch-speaking Flemish in the north, she was obliged to tread carefully. Some Flemish nationalists accused her of not taking them seriously, but she maintained a determined neutrality, and she did take the trouble to learn Dutch, in which she became fluent – as she was in French, German, Italian and English.

It was felt by some that occasionally Fabiola, who had associations with the Opus Dei conservative Catholic movement, wielded too much influence on her husband. Baudouin was enveloped in a major controversy in 1990 when he refused to give a parliament-approved bill legalising abortion his royal assent, one of his constitutional duties. Some partly blamed Fabiola's Catholicism. He stepped down for one day to allow the government to pass the law and was then reinstated.

After he died in 1993 he was succeeded by his younger brother, Albert II. Fabiola moved out of the Royal Palace of Laeken to the more modest Stuyvenberg Castle and reduced her public appearances so as not to overshadow her sister-in-law, Queen Paola.

She often drew as much attention as Paola, however, especially when she became embroiled in a financial scandal. In 2009 she was accused of trying to hide some of her fortune and in a rare public rebuke the then Prime Minister Elio Di Rupo told parliament that he "shared" the strong emotions the scandal had caused among the people.

He called the plan to create a private fund to deal with her inheritance ethically flawed, even if it was strictly legal. Fabiola denied that it was a tax dodge but acknowledged she had "taken the political consequences insufficiently into account" and said she would close the fund.

She was admired for her involvement in social causes, particularly those related to mental health, children's issues and women's issues, and in 2001 the United Nations' Food and Agriculture Organisation awarded her the Ceres Medal for her work championing rural women in developing countries. She also wrote a children's book of fairy stories, donating the royalties to Belgium's National Society for Children.

Although she lived a life of austere simplicity, and received many humanitarian awards, she had a mischievous sense of humour. In 2009 newspapers published anonymous death threats, according to which she would be shot with a crossbow. She responded to the threats during the Belgian national holiday celebrations by waving an apple to the crowd – a reference to the story of William Tell.

Fabiola Fernanda Maria de las Victorias Antonia Adelaida Mora y Aragon, Queen consort of Belgium: born Zurbano Palace, Madrid 11 June 1928; married 1960 King Baudouin I of Belgium (died 1993); died Stuyvenberg Castle, Laeken, Belgium 5 December 2014.