Prince Charles is to attend the canonisation in Rome of one of the most significant figures of 19th-century Britain, joining thousands of pilgrims and well-wishers in St Peter’s Square on Sunday for a ceremony led by Pope Francis.

Cardinal John Newman, who converted from Anglicanism to Catholicism, will be the first English person born since the 17th century to be declared a saint by the Catholic church.

Senior figures from the Catholic church in the UK and the Church of England are also expected to attend the ceremony, along with representatives of the UK government.

Twenty thousand seats will be available in the Vatican’s main square for the occasion, which will be preceded the day before by a symposium on Newman’s life, a prayer vigil and a celebratory concert.

The last Briton to be canonised was the 16th-century Scottish priest John Ogilvie in 1976.

Cardinal Vincent Nichols, the archbishop of Westminster and the most senior Catholic in England and Wales, welcomed Prince Charles’s attendance.

“As one who has been a lifelong champion of the spiritual in everyday life, to promote understanding between faiths, and who has sought to alleviate poverty and disadvantage through his charitable work, the Prince of Wales is particularly qualified to mark the canonisation, which will be such a significant and joyful moment for this country,” he said last month.

Pope Benedict XVI leads a beatification mass for Cardinal Newman at Cofton Park in Birmingham in 2010. Photograph: Max Rossi/REUTERS

The canonisation has sparked fresh interest in Newman’s life. At Birmingham Oratory, a society of priests founded by Newman in 1848, a museum of his personal effects, including robes and manuscripts, will open this autumn. A shrine to the cardinal is being restored, and pilgrims will be able to view a lock of Newman’s hair and a fragment of his bone.

The Pittsburgh-based National Institute for Newman Studies is releasing thousands of documents relating to his life, including letters to the cardinal from British prime ministers Benjamin Disraeli and William Gladstone. As well as letters, prayer lists, notebooks and photograph albums have been digitised.

According to the institute, Newman “stands as a giant in the fields of theology, philosophy and education. Influencing many academic and spiritual disciplines, Newman’s writings and his lifelong search for religious truth continue to inspire scholars throughout the world … His many scholarly works have remained a significant force.”

Newman is regarded as one of the most influential figures from his era, revered for his hymns, poetry and devotion to the people of Birmingham. When he died in 1890, more than 15,000 people lined the city’s streets for his funeral procession.

He was ordained as a priest in the Church of England but converted to Catholicism in 1845 at the age of 44. As well as founding the Oratory of St Philip Neri – known as the Birmingham Oratory – Newman helped to establish the Catholic University of Ireland (now University College Dublin) and was appointed its first rector in 1854.

He was also a novelist and a historian. According to the great Irish author James Joyce, “nobody has ever written English prose that can be compared with that of a tiresome footling little Anglican parson who afterwards became a prince of the only true church”.

Pope John Paul II declared Newman “venerable” in 1991, recognising his life of “heroic virtue”. In 2010, on a visit to the UK, Pope Benedict XVI declared him “blessed”, saying Newman applied “his keen intellect and his prolific pen to many of the most pressing subjects of the day”. Newman continued “to inspire and enlighten many all over the world”, Benedict added.

A second miracle attributed to Newman – the healing in 2013 of a Chicago woman with life-threatening complications in her pregnancy who prayed to the cardinal to save her unborn child – was approved by Pope Francis this year, paving the way to his canonisation.

In 2008, a decision to move Newman’s remains to a new tomb in Birmingham Oratory in preparation for his canonisation was criticised by the gay rights campaigner Peter Tatchell and others.

They argued it contravened his written wish to be buried next to his close friend Fr Ambrose St John. The oratory said the order had come from the Vatican. Tatchell said it was “an act of shameless dishonesty and personal betrayal by the homophobic Catholic church”.