The actress is about to celebrate her 13th wedding anniversary with her husband Percy.
She told 'Hello!' magazine: "It is my fifth marriage, and my happiest, and last. Percy is wonderful, he's my soulmate. That doesn't mean we don't bicker but we are very understanding of each other."
Percy, who shares several homes around the world with the 81-year-old, including houses in Los Angeles and London, said he enjoyed proving people "wrong" who thought the couple would not last.
He said: "I've certainly never been happier and I hope that I make Joan happy because she definitely deserves that."
The former 'Dynasty' star said she had thought about having plastic surgery but was "too scared" to go under the knife.
She said: "I like my laugh lines - it would be crazy not to have any at my age - and luckily I have good cheekbones."
She also revealed she celebrated her recent honour with a raucous celebration, saying: "We took 14 of our closest friends to the Wolseley restaurant in London - and I have to make a public apology to the other diners there that night if our loud renditions of 'There's Nothing Like A Dame' disturbed them."
The full interview is published in the curent edition of in 'Hello!' Magazine
