Lord Carey served as Archbishop of Canterbury from 1991 to 2002 and during his period in office took part in the funeral of Diana, then Princess of Wales, in 1997 and became the first Archbishop to ordain women to the priesthood.
He also reveals how the Queen Consort talked about the earliest days of her relationship with the King during their secret meeting in Peckham.
He said: “She walked through the front door, we met and had coffee together and I was really struck by her.
“Very nice looking lady, very presentable, very intelligent, we had a really animated conversation.
“And we talked about her relationship with Charles, going way back to when they were teenagers and so on. And after she left, I said: ‘Well, there’s no way I could ever treat her as other than a really nice human being who’s deeply in love with Charles.’
“And that affected me in talking to other people behind the scenes and I hoped it had a way forward – I think it did.”
All five episodes of The Real Crown: Inside the House of Windsor are now available to screen on ITVX.