A collection of dresses worn by Diana, Princess of Wales, goes on public display in Toronto Monday ahead of an auction next month.

The Design Exchange is showing the group of 14 dresses, including the midnight-blue silk velvet dress with she wore while dancing with actor John Travolta during a 1985 White House state dinner.

The collection is being sold by American private investor Maureen Rorech Dunkel of Tampa Bay, Fla.

"This collection tells a story. When I originally collected it, I wanted it to visually depict Diana's style transformation through the years," Dunkel told CBC News.

"When she became a princess in the early '80s, she had one look and by the time she became a woman on her own her look had changed dramatically and that's really what the collection is about, it tells that story of her growing up through her fashion."

Dunkel bought the dresses at an auction at Christie's in New York in 1997 for $700,000 US, just eight weeks before the Princess of Wales died in a car accident in Paris.

She was looking for dresses from throughout Diana's life when she bought them. The collection includes luxury creations by British designers such as Bruce Oldfield and Zandra Rhodes, and the late Catherine Walker, one of Diana's favourite designers.

Dunkel said Diana initially allowed designers to guide her fashion choices, but as she matured, she took control of her look.

"They tell us the story of a very young ingenue, you know, who became a princess at the age of 19 and grew to be truly a global style icon who very much directed her own look," she said.

A formal cream coloured silk crepe dinner dress worn by Diana and created by designer Catherine Walker, is part of the collection exhibited at the Design Exchange in Toronto. Canadian Press

Dunkel said it is a "great responsibility" to own such a collection and she has put a lot of work into touring an exhibit of the dresses over the last 14 years.

The Life of a Royal Icon tour travelled to the U.S., Canada and New Zealand and was on display for the past 10 years at Kensington Palace, where Diana once lived. The tour raised money for children's cancer research and for AIDS charities, some of the many causes the late Princess of Wales took on during her life.

"She very much used her style and her fashion and her icon status to help others and so we went down that road after she died," Dunkel said.

The collection goes on auction through Toronto auction house Waddington's on June 23. It is valued at $6 million.

After the display closes at the Design Exchange, Waddington's will host a preview of the dresses from June 21 to 23.

Dunkel said she would like to sell the collection as a whole, possibly to a museum or similar institution, but she is willing to sell the dresses individually.

With files from The Canadian Press