Princess Margaret and Margaret Thatcher exchanged views on crippling industrial action and turbulent world events in a candid correspondence which has been released for the first time.
The letters from 1980 range from hospital visits to the royal's complaint she didn't have a "Trotskyite to argue with!" at a Cambridge debate.
They were made public as part of a series of Cabinet Office files released by the National Archives.
Here's a selection of the choice quotes:
Mrs Thatcher said she "was very distressed" to hear Princess Margaret had been in hospital in a handwritten letter on January 9 1980.
Referring to her stay in hospital, in her response on February 7, the royal told Mrs Thatcher: "I just had to have some things dug out of my face but luckily everything went well."
In the letter, signed "Margaret", the princess wrote: "I went to Cambridge for a debate (rather dull, all about the church, lots of clerics) and found them all rabid conservatives - not a Trotskyite to argue with!
"They were passionately against the Olympic Games in Moscow. I tried the, 'Isn't it hard on the athletes' bit but they were adamant.
"I suppose individuals must choose whether to go as it's up to the Olympic Committee."
Mrs Thatcher praised the Princess for her "wonderfully successful" tour of the United States and - reflecting on her own pre-Christmas trip to the country - said: "I cannot help feeling that Washington is much more isolated from America than London is from Britain."
Iranian hostage crisis
The prime minister referred to the ongoing hostage crisis at the US embassy in Iran, which "dominated every conversation, and understandably so" and, writing two weeks after the Soviet Union invasion of Afghanistan, said events had "cast a shadow over the whole world".
Princess Margaret, addressing world events, admitted to finding it "quite impossible to find out what is happening in Afghanistan".
1980 steel strike
The pair also discussed the first national steel strike in 50 years, which took place in January 1980 following a dispute over pay.
"It is difficult to get across the message that more money has to be earned and not just demanded," Mrs Thatcher wrote.
Princess Margaret described the strike as "depressing" but said: "I suppose if one is an ordinary working man and one's union tells one not to vote for new machinery or technology because otherwise you will lose your job ... you just don't dare."