Roman Catholicism in the United Kingdom
Starting with the Regnans in Excelsis in 1570 and lasting until 1766, the Pope did not recognize the legitimacy of the English Monarchy and called for its overthrow. Therefore by the time of the creation of the Kingdom of Great Britain in 1707, Catholics were discriminated against in England and Scotland in significant ways: in all the kingdoms of the British Isles, they were excluded from voting, from sitting in Parliament, and from the learned professions. These discriminatory laws continued after the Acts of Union 1800 which created the new United Kingdom of Great Britain and Ireland in 1801. At that time, Catholic Emancipation was gathering speed but was not yet a reality, particularly in Ireland, where the Protestant Ascendancy was still in full force.
The Treaty of Union of 1707, like the Act of Settlement, had stated that no "Papist" could succeed to the throne. Restrictions on the civil rights of Roman Catholics only began to change with the passing of the Papists Act 1778, which allowed them to own property, inherit land and join the British Army, although even this measure resulted in the backlash of the Gordon Riots of 1780, showing the depth of continuing anti-Catholic feeling. Over the next half century, an influx of thousands of Catholics fleeing the French Revolution, plus a thawing in relations with the Catholic world during the Napoleonic Wars, when the British were allied with the Catholic states of Portugal and Spain as well as with the Holy See itself, meant that by 1829 the political climate had changed enough to allow Parliament to pass the Roman Catholic Relief Act 1829, giving Roman Catholics almost equal civil rights, including the right to vote and to hold most public offices.
The Great Irish Famine, and the large-scale emigration from Ireland which followed it, led to an increase in the numbers of Catholics in England, Wales and Scotland. In 1850, Pope Pius IX re-established Catholic hierarchies in England and Wales. Scottish hierarchies were restored shortly after, in 1878, by Pope Leo XIII. Since then a number of prominent individuals have converted to Catholicism, including John Henry Newman, Augustus Pugin, Muriel Spark, Gerard Manley Hopkins, G. K. Chesterton, Ronald Knox, Evelyn Waugh, Graham Greene, Malcolm Muggeridge and Joseph Pearce. Members of the Royal family such as the Duchess of Kent and former Prime Minister Tony Blair have also converted to Catholicism, in Blair's case in December 2007 after he had left office.
According to the Central Statistical Office of the Church, Great Britain has a population of 59,381,000 of whom 5,264,000 (8.87%) are Catholics. There are 32 ecclesiastical circumscriptions and 2,977 parishes.
With Catholicism organised by three separate national churches within the worldwide Catholic Church, there is no single hierarchy for Roman Catholicism in the United Kingdom. For details of these separate churches and the history of Catholicism in the countries they serve, see:
- the Catholic Church in England and Wales,
- Roman Catholicism in Ireland (including Northern Ireland and the Republic of Ireland),
- Roman Catholicism in Scotland.
See also 
- List of Roman Catholic dioceses in England and Wales
- List of Roman Catholic dioceses in Ireland (including Northern Ireland and the Republic of Ireland)
- List of Roman Catholic dioceses in Scotland
- Pope Benedict XVI's visit to the United Kingdom
- Religion in the United Kingdom
- The Treaty of Union 1706 scotshistoryonline.co.uk, accessed 15 February 2009 - see article 2
- Roman Catholic Archdiocese of St Andrews and Edinburgh archdiocese-edinburgh.com, accessed 15 February 2009
- "Tony Blair joins Catholic faith". BBC News online. 22 December 2007. Retrieved 2007-11-22.
- Francis Beckett and David Hencke, The Survivor: Tony Blair in War and Peace, 2005, Aurum Press Ltd, ISBN 978-1-84513-110-4
- Francis Beckett and David Hencke, "Regular at mass, communion from Pope. So why is Blair evasive about his faith?",The Guardian, September 28, 2004
- Ruth Gledhill, Jeremy Austin and Philip Webster, "Blair will be welcomed into Catholic fold via his 'baptism of desire'", The Times, May 17, 2007
- Catholic Church in England and Wales
- Catholic Church in Ireland
- Catholic Church in Scotland
- The Holy See — The Vatican's Official Website