The reasons behind terrorist attacks in Great Britain are many. During the 20th century, most attacks were carried out by various Irish Republican Army (IRA) groups and were linked to the Northern Ireland conflict (the Troubles). In the late 20th century there were also isolated attacks by Middle Eastern terrorist groups, though the vast majority of the attacks were the work of the IRA and splinter groups. During the 21st century, however, most terrorist incidents in Britain have been linked to Islamic fundamentalism.

Since 1970, there have been at least 3,395 terrorist-related deaths in the UK, the highest in western Europe."How many people are killed by terrorist attacks in the UK?" . The Telegraph. 5 June 2017. The vast majority of the deaths were linked to the Northern Ireland conflict and happened in Northern Ireland. Between 1971 and 2001, there were 430 terrorist-related deaths in Great Britain. Of these, 125 deaths were linked to the Northern Ireland conflict, and 305 deaths were linked to other causesDouglas, Roger. Law, Liberty, and the Pursuit of Terrorism. University of Michigan Press, 2014. p.18 – most of the latter deaths occurred in the Lockerbie bombing.

List

19th century

13 December 1867: Clerkenwell explosion: members of the Irish Republican Brotherhood (IRB), nicknamed the "Fenians", detonated a bomb against the outer wall of Clerkenwell Prison, in an attempt to free one of their comrades. The explosion damaged nearby houses, killed 12 people, and caused 120 injuries. 1881–1885: Fenian dynamite campaign: the IRB carried out a bombing campaign against infrastructure, government, military, and police targets in Britain. 26 April 1897: A bomb left by an anarchist group on a Metropolitan Railway train exploded at Aldersgate Street station (now Barbican). One person, Harry Pitts, was killed and sixty were injured, ten seriously.

1912–1914 From 1912 to 1914, the female enfranchisement movement, the suffragettes, orchestrated a bombing and arson campaign which was described by the suffragettes themselves as terrorism. Emmeline Pankhurst said the suffragettes committed these acts to "terrorise the British public" and the Women's Social and Political Union reported their own acts as a "Reign of terror". The campaign included burning down the houses of members of the cabinet, an axe being thrown at the Prime minister, attempted bombings of train stations including with nail bombs, and attempts to flood towns by attacking water courses. C.J. Bearman asserts that there were at least 337 arson or bombing attempts and that the cost of the campaign in 2021 money amounted to 140-240 million pounds. 1300 people had been arrested and imprisoned by the end of the campaign.

1939–1940 From January 1939 to March 1940, the Irish Republican Army (IRA) carried out a campaign of bombing and sabotage against the civil, economic, and military infrastructure of Britain. It was known as the S-Plan or Sabotage Campaign. During the campaign, the IRA carried out almost 300 attacks and acts of sabotage in Britain, killing seven people and injuring 96.Dingley, James. The IRA: The Irish Republican Army. ABC-CLIO, 2012. p.82 Most of the casualties occurred in the Coventry bombing on 25 August 1939.

1970s

12 January 1971: Two bombs exploded at the house of government minister Robert Carr. This attack was one of 25 carried out by the Angry Brigade between August 1970 and August 1971. The Bomb Squad was established at Scotland Yard in January 1971 to target the group, and they were apprehended in August of that year. 31 October 1971: A bomb exploded in the Post Office Tower in London causing extensive damage but no injuries. The "Kilburn Battalion" of the IRA claimed responsibility for the explosion, but The Angry Brigade also claimed to have carried out the attack. It was likely the work of the Angry Brigade and not the IRA.Bomb explodes in Post Office tower On this day report by the BBC 22 February 1972: Aldershot bombing: The Official Irish Republican Army ('Official' IRA) detonated a car bomb at Aldershot British Army base, Hampshire. The blast killed seven civilian staff. 19 September 1972: The Palestinian terrorist group Black September posted a letter bomb to the Israeli embassy in London killing an Israeli diplomat.Parcel bomb attack on Israeli embassy On this day report by the BBC 8 March 1973: The Provisional Irish Republican Army ('Provisional' IRA) planted four car bombs in London. Two of the bombs exploded outside the Old Bailey and the Ministry of Agriculture, injuring dozens. The bombs outside New Scotland Yard and an army recruitment office near Whitehall were defused. 10 September 1973: The Provisional IRA set off bombs at London's King's Cross and stations, injuring 21 people.Bomb blasts rock central London On this Day report by the BBC 18 December 1973: 1973 Westminster bombing: An IRA car bomb exploded outside the Home Office building in Millbank, London, injuring 60 people. 4 February 1974: M62 coach bombing: An IRA bomb exploded aboard a bus carrying British soldiers and several of their family members in Yorkshire, killing nine soldiers and three civilians. 26 March 1974: Claro Barracks at Ripon, North Yorkshire; Two stores and the main NAAFI building were damaged by three IRA bombs planted by Peter McMullen. Another device was then destroyed in a controlled explosion by army bomb disposal experts in the main barracks, where 100 soldiers had been sleeping. The 49-year-old manageress of the NAAFI shop suffered facial cuts from flying glass during the attack. 11 June 1974: Queen Elizabeth Barracks, Strensall near York, North Yorkshire; A bomb (thrown over the perimeter fence?) destroyed most of the Green Howards Band's musical instruments. 17 June 1974: Houses of Parliament bombing: An IRA bomb exploded at the Houses of Parliament, causing extensive damage and injuring 11 people.IRA bombs parliament On this day report by the BBC 17 July 1974: Tower of London bombing: A bomb exploded in the Tower of London, killing one and injuring 41. 5 October 1974: Guildford pub bombings: IRA bombs exploded in two pubs frequented by off-duty British military personnel in Guildford, Surrey. Four soldiers and a civilian were killed, and 44 were injured. 22 October 1974: An IRA bomb exploded in Brooks's gentleman's club in London, injuring three people.Bomb blast in London club On this Day report by the BBC 7 November 1974: An IRA bomb exploded in a pub frequented by British military personnel in Woolwich, London, killing a soldier and a civilian. 14 November 1974: James Patrick McDade, a Lieutenant in the Birmingham Battalion of the Provisional Irish Republican Army (IRA), was killed in a premature explosion whilst planting a bomb at the Coventry telephone exchange in 1974. 21 November 1974: Birmingham pub bombings: IRA bombs exploded in two pubs in Birmingham, killing 21 people and injuring 182. 18 December 1974: 1974 Bristol bombing: Two IRA bombs exploded in one of Bristol's shopping districts in the run-up to Christmas, injuring 17. Report 27 January 1975: An IRA bomb exploded at Lewis's department store in Manchester, England. Following a warning telephoned to the Press Association at 16:07, the bomb exploded 17 minutes later injuring 19 people, one of them seriously. Seven bombs were also planted in London; five of them exploded, injuring six people. 27 August 1975: Caterham Arms pub bombing: An IRA bomb exploded in a pub frequented by British military personnel in Caterham, Surrey, injuring 33. 5 September 1975: An IRA bomb exploded in the lobby of the Hilton Hotel, London, killing two people and injuring 63. 9 October 1975: Green Park tube station bombing: An IRA bomb exploded by Green Park tube station in London, killing one. 18 November 1975: IRA members threw a bomb into Walton's restaurant in London, killing two people and injuring 23. 27 November 1975: IRA gunmen assassinated political activist and television personality Ross McWhirter in Enfield Town, London. 6–12 December 1975: Balcombe Street siege: Four IRA members, who were fleeing from the police, barricaded themselves inside a flat in London and held the two occupants hostage. The siege lasted for six days and ended when the IRA members surrendered and released the hostages. 20 December 1975: Biddy Mulligan's pub bombing: The Ulster Defence Association (UDA) bombed Biddy Mulligan's pub in the Kilburn area of London. Five people were injured. It said it bombed the pub because it was frequented by Irish republican sympathizers."Bomb in pub - City police hold 4" . Evening Times, 20 December 1975. 4 March 1976: Cannon Street train bombing: An IRA bomb exploded in an empty train at Cannon Street station in London, injuring eight. 15 March 1976: West Ham station attack: An IRA bomb exploded on a train at West Ham station in London, injuring seven. The bomber then shot two people while fleeing, killing one. 27 March 1976: Olympia bombing: An IRA bomb exploded at the Olympia, London, killing one and injuring more than 80 people. 31 December 1977: An explosive device detonated inside the passenger compartment of a car owned by the Embassy of the Syrian Arab Republic, killing two members of the Syrian embassy staff. 17 December 1978: Co-ordinated IRA bombs exploded in Manchester, Liverpool, Coventry, Bristol, and Southampton, injuring at least seven in Bristol. 17 January 1979: A bomb exploded at a Texaco oil terminal on Canvey Island, Essex, tearing a hole in a tank that was initially thought to contain aviation fuel. 17 February 1979: Glasgow pub bombings: The Ulster Volunteer Force (UVF) bombed two pubs frequented by Catholics in Glasgow, Scotland. Both pubs were wrecked, and several people were wounded. It said it bombed the pubs because they were used for Irish republican fundraising.Wood, Ian S. Crimes of Loyalty: A History of the UDA. Edinburgh University Press, 2006. p.329 30 March 1979: Airey Neave killed when a bomb exploded under his car as he drove out of the Palace of Westminster car park. The Irish National Liberation Army (INLA) claimed responsibility.

1980s

30 April 1980: Iranian Embassy siege: Six Iranian Arab gunmen stormed the Iranian Embassy in London and took hostages. The siege lasted for six days, until the hostages were rescued in a raid by the SAS, which was broadcast live on TV. Two of the hostages were killed, while the hostage-takers were all either killed or captured. January 1981: Bomb inside the RAF band barracks in RAF Uxbridge. A security patrol discovered the bomb surrounded by drums of petrol. The barracks were evacuated, but the device exploded before the bomb disposal arrived. The blast was heard up to 2 miles away. There were two minor injuries. 10 October 1981: The IRA detonated a bomb outside Chelsea Barracks, London, killing two and injuring 39. 26 October 1981: The IRA bombed a Wimpy Bar on Oxford Street, killing Kenneth Howorth, the Metropolitan Police explosives officer attempting to defuse it. 14 March 1982: The bombing of the London offices of the African National Congress (ANC), which opposed the apartheid government of South Africa, wounding one person who was living upstairs. General Johann Coetzee, former head of the South African Security Police, and seven other policemen accepted responsibility for the attack after the end of the apartheid government. 20 July 1982: Hyde Park and Regent's Park bombings: IRA bombs exploded during British military ceremonies in Hyde Park and Regent's Park, London, killing eleven soldiers of the Household Cavalry and the Royal Green Jackets. 17 December 1983: Harrods bombing: An IRA car bomb exploded outside Harrods department store in London, following a telephoned warning. Five people were killed, including three police officers, and the sixth victim – another police officer – died in hospital from his injuries a week later. 90 other people were injured but survived.