Thanksgiving service for The Tablet's 175th birthday
The 175th birthday of Catholic journal The Tablet is due to be celebrated with a thanksgiving Mass at Westminster Cathedral.
First published in 1840, The Tablet is the second oldest surviving weekly journal in the UK, after The Spectator.
The Mass, led by the Archbishop of Cardiff, George Stack, will begin at 14:00 BST.
It will feature the world premiere of a special commission by classical composer Roxanna Panufnik.
Literary editor Brendan Walsh told the BBC: "We're expecting a memorable liturgical occasion and a lovely party."
With readers invited to join the editor, staff and contributors for the Mass and for a reception afterwards, he added: "The Tablet is a friendly, exuberant, sometimes rumbustious family, with a close bond between its readers and its editors and writers, and the journal has always stood for a respectful, lively and open conversation in the household of the faith."
The Tablet is far older than Westminster Cathedral itself, the Roman Catholics' mother church in England and Wales, which first opened its doors to the public in 1903.
Founded more than 60 years earlier, in the year that Queen Victoria married Prince Albert and the Penny Black stamp was first used, the magazine was set up by Frederick Lucas, a Quaker convert to Catholicism.
The journal has covered the reigns of 13 Popes in the years since, with writers Evelyn Waugh and Graham Greene among its contributors.
Its aim at the time was to record the news of interest to a Catholic population that was growing fast, thanks partly to immigration from Ireland - with the number of Catholics in England rising from around 80,000 in 1770 to 750,000 in 1850.
Parliament had recently passed the Roman Catholic Relief Act in 1829, giving Roman Catholics the right to vote and hold most public offices.
However, by the 20th Century, the journal's liberal stance on contraception in the 1960s apparently brought "sorrow and disappointment" to Pope Paul VI.
Today, there are more than five million Catholics in the UK, and the journal remains the voice of much of the laity.
In recent years its pages have included contributions from figures such as former Prime Ministers Tony Blair and Gordon Brown, the journalist John Cornwell and concert pianist Stephen Hough.
Celebrating its birthday edition with a list of the Top 100 lay Catholics of 2015, the magazine placed Bank of England governor Mark Carney in first place.
Editor Catherine Pepinster says the magazine's longevity - despite the tempestuous history of Roman Catholicism here - is testimony to the capacity for minority groups to thrive in Britain.