Fourteen dresses that were once worn by the late Princess of Wales will be auctioned off in Toronto on Thursday.

The collection is valued at an estimated $175,000 to $1,250,000. It includes a Victor Edelstein green silk velvet dress worn by Diana at private dinner parties at Kensington Palace, and a Catherine Walker halter dress worn by Diana for a Vanity Fair photo shoot.

The auction will take place at Waddington's auction house with a portion of the proceeds going to the National Ballet School.

"Many people remember watching Diana grow up through her fashion," said Maureen Dunkel, the current owner of the collection.

Dunkel said she purchased the dresses as an investment in June of 1997, eight weeks before Diana died. Dunkel said she wanted a minimum of a dozen dresses to represent Diana's style transformation throughout the years.

She said she bought the dresses from a private company and did not reveal how much she initially paid for them.

Dunkel said she didn't have an appreciation for who Diana really was when she first bought the collection.

"I didn't understand truly the treasure I had until after she died and I started learning more and more about her. My heart has really grown for the collection over the years," said Dunkel.

The collection also includes the infamous midnight-blue velvet dress that Diana wore while dancing with John Travolta at a White House state dinner in 1985.

"A princess in the White House, a president (and) a movie star. All of those ingredients make it such a historic piece," said Dunkel.

The collection has toured around the world to raise money for charity and was kept at the late Princess' former home of Kensington Palace for 10 years.

Dunkel said it was a good time to sell the dresses because of the renewed interest in the Royals after the recent wedding of the Duke and Duchess of Cambridge.

The collection of dresses will be on display at Waddington's at 111 Bathurst St. on Wednesday from 10 a.m. to 9 p.m. and Thursday from 10 a.m. to 2 p.m. The auction is set to begin on Thursday at 7 p.m.