Charles was long vilified both for the extra-marital affair, which was blamed for the breakup, and in part for the royals' poor initial handling of Diana's death, when they were widely criticised for appearing heartless and out of step with the public.
However, he has gradually won back some public support and begrudging acceptance that he has found happiness with Camilla, whom he married in 2005.
Charles has courted controversy for speaking out and appearing to pressure politicians privately, on various contentious public issues from health to the environment.
In a now-infamous series of letters between him and government ministers known as the "black spider" memos because of his scrawled handwriting, Charles quizzed them on an array of topics.
Made public in 2015 after a decade-long legal battle waged by The Guardian newspaper, they included the plight of the Patagonian Toothfish and his famous bugbear, modernist building schemes.
Charles's opposition to bold new design first grabbed public attention in 1984 when he likened plans for altering the National Gallery in London to adding a "monstrous carbuncle on the face of a much-loved and elegant friend".
The disclosure of the "black spider" letters sparked a backlash against the then-future king and concerns he was overstepping his role.
However, in a 2018 interview marking his 70th birthday, Charles insisted he never directly meddled in party politics and understood the difference between being Prince of Wales and monarch.
More recently, Charles has become embroiled in an alleged cash-for-honours scandal.
A series of newspaper revelations claimed his close aides coordinated work to grant a royal honour and even UK citizenship to a Saudi businessman who donated large sums to restoration projects of particular interest to Charles.
Michael Fawcett, his former valet who rose through the ranks to become chief executive of his charitable foundation, resigned in 2021 following the launch of an internal investigation into the accusations.
It was the latest claim to tarnish Fawcett -- and, by association, Charles.
In 2003, Fawcett resigned after being accused of bending palace rules and accepting valuable royal perks.
He was later cleared of allegations of financial misconduct over the sale of unwanted royal gifts, but an internal report found various members of Charles's household guilty of "serious failings".
