In 1974, George Montague was convicted of gross indecency with a man.
For many years Montague, who calls himself the "oldest gay in the village" has campaigned passionately for an apology from the UK government for the under the Criminal Law Amendment Act of 1885 which criminalised male homosexuality, even after it was legalised in 1967 in England and Wales.
Now, at the age of 93, the man from Brighton has received the apology he has waited 43 years for.
"I opened my mail and I found that letter," Montague tells the Press Association.
"That was the most wonderful thing that ever happened to me in my life. I still can't believe it."
Montague married his partner Somchai Phukkhlai in 2015, but had three children with a wife of 22 years, until he came out in 1982.
"I lived a lie for about 30, 40 years of my life," Montague says.
"Now, there ain't a gay guy in the world that is out as much as I am."
Three years ago Montague published The Oldest Gay in the Village, a memoir of his experiences as a gay man.
Following his conviction, Montague was fined $180. He was also forced to resign as a senior commissioner in the Boy Scout Association, where he ran camps for disabled boys.
Last year Montague delivered a petition with almost 15,000 signatures to Downing Street asking for an official apology before he dies, saying his only crime was "being born only able to love or be in love with another man".
He says the apology was necessary.
"You think about it and you think about it, and you think how hurt you've been about the way you were treated," he says.
"You think yes, an apology is needed. It is called for and it is just - and we've got it."