Transcript for Inside the moment Prince Harry asked his dad to walk Meghan Markle down the aisle

A new documentary by the bbc gives an unprecedented look at the man who will be king. Prince Harry revealing for the very first time what happened between father and son when Meghan's father bow the out of the wedding. I asked him to. I think he knew it was coming and immediately said, yes, of course, I'll do whatever Meghan needs and I'm here to support you. Reporter: Prince Harry whispering thank you, pa, at the altar showing the new bond. Just because he's my father doesn't mean I can go, that's it, I'll take it from here. I was grateful. Reporter: Camilla giving a glimpse into a side of Charles we rarely see, a devoted grandfather adored by his grandchildren. He will get on his knees and crawl about them for hours, making funny noises and laughing. He reads Harry potter. He can do all the different voices and I think children really appreciate that. Reporter: A man described by his sons as committed to his work and beloved by his family. I would like him to have more time with the children so having more time with them at home would be lovely and being able to play around with the grandchildren. Reporter: Charles speaking for the first time answering criticism on how he will one day rein. Some have accused you of meddling. Really? You don't say. I won't be able to do the same things I've done, you know, as heir. I'm not that stupid. I do realize that it is a separate exercise being sovereign. Prince Charles becoming a grandfather again this coming spring. Charles turns 70 next Wednesday

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