The Princess Royal confronted an armed man trying to kidnap her in 1974, saying his plot was not "bloody likely" to work, declassified papers have said.
Four people were injured in the March 1974 incident
Ian Ball, a 26-year-old burglar with mental health problems, ambushed Princess Anne's car in the Mall, London, one night in March 1974.
He had asked her to "come with me for a day or two" because he wanted £2m.
Papers released under the 30-year rule show the Princess told him "bloody likely, and I haven't got £2m".
The briefing has been released by the National Archives.
In the document, written for prime minister Harold Wilson, the Princess said the only thing that had stopped her from hitting Ball was the thought that he would shoot her.
"It was all so infuriating; I kept saying I didn't want to get out of the car, and I was not going to get out of the car," she said.
"I nearly lost my temper with him, but I knew that if I did, I should hit him and he would shoot me."
Ball was apprehended after shooting and wounding two police officers, Princess Anne's driver and a journalist who had been following in a taxi.
Ball fired 11 rounds after using his Ford Escort car to stop the Princess Anne's vehicle. She, her then husband Mark Phillips and her lady-in-waiting were thrown to the floor.
Ball was finally subdued by another police officer who brought him down with a flying tackle as he tried to get away.
Ball later pleaded guilty to charges of attempted murder and attempted kidnap and was imprisoned indefinitely under the Mental Health Act.
The government file also confirms that Ball was working alone.
Mr Wilson wrote in green pen at the top of the file: "A
very good story. Pity the Palace can't let it come out. Perhaps it will in court. HW"
He praised the Princess' bravery, saying she had behaved with "quite extraordinary courage and presence of mind".
Other revelations from the batch of documents include:
- Harold Wilson wanted nuclear submarines to power Belfast during the 1974 Ulster Workers' Council Strike.
- The Labour government considered introducing identity cards in 1974 amid terrorism fears, but scrapped the idea as too expensive and ineffective.
Ministers dismissed the strike, which wrecked a 1974 power-sharing deal in Northern Ireland, as the "last fling" of loyalist extremists
- Ministers encouraged links between rival paramilitaries at the height of the Northern Ireland Troubles
- The relationship between Harold Wilson and his industry secretary Tony Benn reached "rock bottom" in 1974
- Tory Prime Minister Edward Heath secretly considered serving under his arch
rival, Harold Wilson, in a "Government of National Unity" in the aftermath of the inconclusive 1974 election
- Ugandan dictator Idi Amin offered to save the UK from financial ruin, and suggested he could broker peace in Northern Ireland
- Israeli secret services targeting Ali Hassan Salame, the Palestinian behind the killing of 11 Israeli athletes at the Munich Olympics, killed a Moroccan catering worker in Norway by mistake