(LONDON) Around 1,500 items from Queen singer Freddie Mercury, including stage costumes, handwritten lyrics and even works by Matisse and Picasso, will be auctioned in London in September, Sotheby’s announced on Wednesday.

Prior to the sale, key pieces from these auctions will be exhibited in New York, Los Angeles, Hong Kong in June, then in London from August 4 to September 5.

Among the items that will go under the hammer are a crown, inspired by that worn by British sovereigns during their coronation, and a faux fur and red velvet cape.

These two pieces are inseparable from the flamboyant British artist: Freddie Mercury wore them to sing God Save The Queen during his last tour with the group, The Magic Tour, in 1986. They are estimated between 60,000 and 80,000 pounds sterling (102 000 to $136,000).

Another important piece of the sale: handwritten lyrics by the singer, on nine pages, of the song We Are The Champions, one of the best known of the group. The price is estimated between 200,000 and 300,000 pounds ($340,000 and $510,000).

An acoustic guitar by Freddie Mercury, who died of AIDS in 1991, will also be on sale, as will works by Picasso and Matisse that belonged to him.

These objects, which were in his former house in the wealthy district of Kensington in London, are sold by Mary Austin, one of the closest friends of the artist, who was also his partner.

“For many years I had the joy and privilege of living surrounded by all those wonderful things that Freddie sought out and loved so much. But the years have passed and the time has come for me to make the difficult decision to close this very special chapter of my life,” she said, as quoted by Sotheby’s.

“I hope this will be an opportunity to share the many facets of Freddie, both public and private, and for the world to better understand and celebrate his unique and beautiful spirit,” she added.

Sotheby’s estimates the sale will reach at least £6 million (over $20.2 million). Profits will be donated in part to the Mercury Phoenix Trust and Elton John Aids Foundation, two organizations involved in the fight against AIDS.