A precious fragment of the shroud of Edward the Confessor and ancient royal manuscripts will be laid on the high altar at Westminster Abbey during a service to celebrate the 750th anniversary of the gothic church.

The abbey was consecrated on 13 October 1269 after Henry III rebuilt a basilica constructed on the same site by St Edward, the Anglo-Saxon king and the first English saint to be canonised by Rome.

The Queen and the Duchess of Cornwall will attend the anniversary event on Tuesday where some of the abbey’s most beloved treasures will be on show. King Edgar’s grant of land in 960 enabling the establishment of the very first Benedictine monastery where the abbey now stands will be placed on the altar. The 14th-century Litlyngton Missal will be opened alongside it.

Two elaborate 13th-century manuscripts signed by Henry III are on public show for the first time in the abbey’s galleries. In tightly written ink script on vellum (calf skin) and with impressive wax seals on silk cords, they reveal Henry’s wish to be buried in his new church alongside Edward, whom he venerated. They also reveal his pawning of gold, precious stones and jewels when he ran into financial difficulty during the extravagant rebuilding.

Facebook Twitter Pinterest A 1267 inventory of Edward the Confessor’s shrine listed the huge amount of gold, precious stones and jewels taken from the shrine to be pawned by a cash-strapped Henry III. Photograph: Dean and Chapter of Westminster

For centuries, Westminster Abbey has been at the centre of national life, and it has been described as Britain’s Valhalla, after the burial hall of Norse mythology.

The Very Rev Dr John Hall, the dean of Westminster, said: “I don’t think there is anywhere in this country that has precisely this link with our nation’s history.”

Sovereigns have been crowned, married and buried here. Countless heads of state have laid wreathes on the grave of the Unknown Warrior. Some of the country’s leading figures are interred or commemorated within its walls, including Geoffrey Chaucer, Isaac Newton, Charles Darwin and Charles Dickens.

On visiting in 2011 when he was US president, Barack Obama exclaimed: “Here you have the history not only of England and Great Britain but of the Commonwealth and the whole of the English-speaking world.”

The site’s exact history is still a mystery. Monks may have founded a small community here as early as 604. When the Confessor chose the spot to establish his palace, which eventually would become the Palace of Westminster, he built a new monastic church. His Romanesque basilica is depicted in the Bayeux tapestry.

Henry III, a devotee of Edward, began the creation of the abbey as it is known today. The famous west towers would not be added until 1745.

“Westminster Abbey was here before anything else,” said Hall. “We were two miles south-west of London and on a remote damp little island, Thorney Island, just surrounded by tributaries of the Thames and the Thames itself. Now we have the Palace of Westminster, the supreme court, the government offices in Whitehall. So now the centre of government is around here and the abbey is very much part of that particular community.”

Facebook Twitter Pinterest The coronation chair at Westminster Abbey. Photograph: Dean and Chapter of Westminster

Links with royalty and parliament go back centuries. With two exceptions, every English and, subsequently, British monarch has been crowned here since William the Conqueror in 1066.

“The Confessor and the Conqueror were the first sovereigns to associate themselves closely with the abbey, and they also made Westminster their place of residence and the seat of government, hereby connecting church and state in a bond that has lasted and evolved across the subsequent millennium,” writes the historian and president of the British Academy, Sir David Cannadine, in Westminster Abbey: a Church in History, published to mark the 750th anniversary.

It survived Henry VIII’s dissolution by becoming a cathedral. Mary I re-established it as a monastery. Elizabeth 1 established it as a royal peculiar – answerable to the sovereign and outside the jurisdiction of the Church of England – and named it the Collegiate Church of St Peter, Westminster.

Its status as a royal peculiar means other faiths can pray there. It is for all faiths and none. In recent years its services have marked the anniversaries of the Srebrenica massacre, of Kristallnacht, of the liberation of Auschwitz, of the death of Martin Luther King. Its annual Commonwealth Day service is invariably attended by the Queen.

Its fame has been fanned by televised ceremonies including the wedding of the Duke and Duchess of Cambridge and the extraordinary funeral of Diana, Princess of Wales. It attracts 2 million tourists and worshippers a year.

“It has been a house of prayer and devotion for much more than a millennium. It is a building of outstanding architectural significance and an unrivalled national mausoleum,” said Cannadine. “It’s close and lengthy relations with the parliaments of governments of this country are unequalled by any other church in any other nation.”