Transcript for A rare look at a young Princess Diana in home videos
George. A lot of good advise here with Jess Cagle. Also the executive producer of a new look at the life of princess Diana 20 years after her death. Her family showing home video in a new ABC special "The story of Diana." Long before the fairy tale wedding and the heartache, a baby named Diana. In these rarely seen home videos from her younger brother Charles, the future princess, a child at play. You would be wrong to think of Diana as a saintly child. She was quite naughty. Never with malice, just sort of pushing the boundaries. Reporter: She pushed those boundaries as princess too before he life was cut short at 36 in a Paris car accident. Diana's driver recalled escorting her body home. Come into a seat where you can't move with people, but as we came out of the airport and turned left which is the a-40 INT inter-london, no cars, people. People upon people upon people. All the way in, must have been probably 4 for 5 miles. Reporter: Two decades after her death her memory lives on through the sons she adored and the grandchildren she never met. One of the great tragedies, of course, is that Diana would have been the best grandmother ever. I love the fact that there's such veneration among her immediate family for what she was and what she meant and I think that's fantastic. Boy, Jess, so special to see those home movies. Right. There's a lot of footage of Diana, especially as a young girl that we've never seen before. Photo, a lot of people like Charles Spencer, her brother, who have not spoken a lot over the years and just give tremendous insight into who this woman was. What surprised you the most. It surprised me to know, one, how muc( she loved prince Charles. You know, it's fascinating she was a wide-eyed romantic and when she married the prince, she really thought that was going to be forever. He had very different ideas about marriage. That anger we see later real heartbreak. Real heartbreak but also what you learn in this documentary is that she was really strong and really formidable from a very, very young age. Much stronger than the blushing bride that we sort of saw in the beginning of the marriage. Even those first pictures of her, that same mischievous look in her eyes. She was very smart and had she I'm sure decided to become an actress she would have been a great actress because every emotion she ever had plays out right there on her face and this documentary plays out over four hours and you see the changes in her particularly in the way she reels to the media and the way she relates to prince Charles and this sort of fearsome righteous anger she had. It was all right there on the fast. 20 years after her death he still captures our attention. She does. This was a fairy tale that became a soap opera that became a tragedy. It's one of the most compelling human lives ever lived and it's told from the point of view of people who knew her, her brother, people who worked for her, really close friends that were there, eyewitnesses for, you know, the marriage and the dissolution of the marriage and in the way she sort of pulled herself up and really became a voice for the disenfranchised of the world and really set the bar for the way that celebrities should use fame. A tremendous impact. Very powerful story. Jess, thanks for bringing it to us. You can see part one tonight at 9:00 P.M. Eastern. Part two tomorrow night.
This transcript has been automatically generated and may not be 100% accurate.