Today, Charles Earl Spencer came to Seattle to help keep that promise.

He has found a creative way to keep their family estate, Althorp, just as it was when he and Diana were growing up.

Princess Diana's brother has created a living history furniture collection.

"I was brought up to look after Althorp," he said. "It was drummed into me at a very young age, that it would be mine to have, not in a way to enjoy it and abuse it in any way, but very much as a duty that I should look after this piece of Britain's heritage."

And Spencer is doing just that, but in a most unusual way.

"The house has been looking after the furniture for hundreds of years, it's time for the furniture to look after the house."

The house where Diana once lived and her brother and his family now live cost $1 million annually to operate. That doesn't include the upkeep and restoration.

That's where the home's 500-year-old furniture comes in.

Spencer is now in the furniture making business, selling to select stores in the U.S., including Bellevue's Masins Fine Furnishings.

Each piece is a replica of furniture from the Spencer Estate, which has been in the family for 19 generations.

"This is a chair from the library," says Spencer, perched on a proper and plump yellow wing back chair.

For $2,500, it's yours. Or you can break bread at a replica of the pencer's formal dining table. It's a mahogany round table, with wooden cutouts that turn a giant table instantly smaller. That's just under $12,000, chairs not included.

Every dollar earned goes right back into the house for repairs and restoration.

Spencer says the upkeep became such an enormous undertaking, it came down to selling the home's world famous art and furniture or finding another way. For the family's sake he found another way.

"Obviously Diana, by a million times, is the most important Spencer who has lived there," says Spencer.

In droves, tourists flock every year to Althorp. They come to connect with Diana. She's buried here, and a 6 room exhibition depicts her life and work. And then there's Althorp, one of her childhood homes.

"The combo is interesting, the house gives a context to Diana and the exhibition," Spencer said.

Spencer's goal is to leave Althorp better than when he inherited and keep a princess' legacy alive.

"It's a sort of ongoing lifetime job really."