With such constant instability and betrayal, the union dramatically deteriorated and the pair eventually separated in 1992 and divorced in 1996, supposedly at the Queen's insistence.
It was without a doubt one of the most high-profile divorces in British history, but the terms of the divorce were often kept from the public eye.
According to Express.co.uk, the people's princess won a heart-stopping £17million lump sum – approximately $56 million Australian in today's money - and an additional £400,000 – around $1.3 million today – as an annual allowance.
According to royal biographer Tina Brown, the Princess of Wales made a series of clever manoeuvres to secure the settlement.
In The Diana Chronicles Brown writes: “The Prince was first stunned, then outraged, when, in April [he was] presented with Diana’s final £17million term.”
“The Princess held a high card: while Prince Charles was now desperate to be rid of her, she could wait."
Brown continued: “In May, Diana went to the Queen and told her that unless her terms were met she would withdraw her consent to divorce.
“Without it, Charles would have to wait another two years until the obligatory five have had been reached for a non-consenting divorce.
“If she ran out of money, she would sell her jewels in order to live and that would be a great embarrassment.”
According to the royal biographer, Charles was enraged by the total figure, and even attempted to go over Diana's divorce lawyer and straight to the head of the firm Lord Mishcon, to try to reduce Diana’s demands.
Ms Brown writes that Charles' efforts were in vain: “On July 13, the divorce deal was sealed on the terms Diana asked. It was a sweet clear victory.
“She may have lost her title but she had won financial independence of the first time in her life.”