Think of an attempt to blow up Parliament, and you think back to 1605, Guy Fawkes and the Gunpowder Plot.
In 1974, though, there was another attempt to blow up the Houses of Parliament — and this one was relatively successful.
"I looked through Westminster Hall and the whole hall was filled with dust. A few minutes later it was possible to see flames shooting up through the windows," then-Liberal chief whip David Steel told the BBC at the time.
At around 8.22am on 17 June 1974, the Press Association had received a call — apparently from the IRA — informing them that a bomb was set to go off in Parliament. Six minutes later, there was an explosion near the ladies' toilets in Westminster Hall; a large fire broke out, and 11 people were injured.
The following day, MPs and security chiefs discussed the bombing, and what could be done to foil future attempts — the upshot, apparently, was a combination of philosophical shoulder-shrugging and calls for the reinstatement of the death penalty. Though the hall obviously had to be restored, the bombing is rather snubbed by Parliament's official restoration and renewal timeline. Instead, 1974 is noted for "Underground car park beneath New Palace Yard completed" and "Reproduction Pugin wallpaper provided for the Moses Room under the guidance of the Victoria and Albert Museum".
The IRA attack was, of course, not the first successful bombing of Parliament; it was bombarded during the second world war — hit, in fact, during 14 separate raids and suffering extensive damage, including the gutting of the Commons Chamber and broken glass on Big Ben's south face (Big Ben continued to chime throughout the war). On 10 May 1941, three people were killed.
Second world war bombs continue to haunt Parliament; the latest to prompt a safety concern was in January 2017, when an explosive was dredged up from the Thames, and Westminster station was evacuated as a precaution.
That leaves us with a total of 15 successful bombing attempts on the modern Palace of Westminster. But we have found evidence of at least one further explosion. On 29 June 1886 — just 16 years after the new Houses of Parliament was completed — Charles Morney descended into the sewers beneath the palace, with the intention of inspecting them. Unfortunately, he did this with the aid of a lamp, which ignited a build up of gas, and caused a great explosion. Said the Western Daily Press two days later, "Morney was severely scorched about the face, and his wrists and arms were badly burnt."
Morney, ironically, suffered far greater injuries than the majority of those in the IRA bombing of 1974.