Michael Palin has said he and the other members of the Monty Python comedy troupe will rally around Terry Jones as he battles dementia.
Michael, 73, presented Terry, 74, with a Bafta Cymru award for his contribution to film and television at the weekend.
Welsh-born Terry is suffering from primary progressive aphasia, which is a form of dementia that affects his ability to communicate.
Michael told the Radio Times he had been aware that Terry's memory was failing for a number of years.
He said: "This is progressive and the loss of the ability to speak is one of the things it brings.
"I grew up with a father who stammered and that was difficult enough for him. But for words just not to even be there, not to utter anything, it's a terribly sad thing to befall anyone.
"I saw John (Cleese) yesterday and there's nothing much we can do but stand there and say, 'Oh God, what has happened to our friend?' But the Pythons will rally round."
Michael and Terry were members of the famous group, which also included John Cleese, Terry Gilliam, Eric Idle and Graham Chapman.
Terry Jones directed Monty Python's Life Of Brian and Monty Python's The Meaning Of Life. Alongside Terry Gilliam, he co-directed Monty Python And The Holy Grail.
In 2014, the remaining Monty Python co-stars re-united for a series of live shows at London's O2 arena, to pay a £800,000 legal bill after losing a royalties case against Mark Forstater.
The group lost the case to Forstater, the producer of their second film Monty Python And The Holy Grail, over its musical version Spamalot.
The shows were, according to Michael, one of the bravest things he has ever done.
He explained: "Having to be as good as we were 40 years ago or people would say, 'Oh, it's a load of old farts just staggering on stage'."
The seasoned broadcaster's latest project sees him travelling to north Wales to meet travel writer Jan Morris, who was part of the 1953 team who successfully scaled Mount Everest.
Morris was born James Morris and transitioned from a man to a woman in 1972.
Read the full interview in this week's Radio Times.