The Notorious B.I.G.’s crown, Tupac’s love letters and other hip hop treasures will be up for auction next month. Included in an auction at Sotheby’s in New York, the artifacts and over 120 other items will be sold as a commemoration of hip hop’s history and cultural impact.

“Since its birth in the Bronx in the 1970’s, hip hop has become a global cultural force, whose massive influence continues to shape all realms of culture — music, fashion, design, art, film, social attitudes, language and more,” Sotheby’s Books & Manuscripts Department Vice President and Senior Specialist Cassandra Hatton said in a statement.

“This sale is a celebration of the origins and early eras of that influence,” she added. “We are pleased to announce the auction with two renowned and beloved icons whose lives and lyricism continue to resonate—Biggie and Tupac—with lots that offer an introspective look, in their own way, at the personalities behind their respective public personas.”

Biggie’s crown was pictured in his famed K.O.N.Y. (King Of New York) portraits, photographed three days before his death by Barron Claiborne. Complex reports that Claiborne offered up the crown to be auctioned, as well as three specially sized prints of the rapper’s 10th anniversary K.O.N.Y. portrait and the contact sheet. All three items are estimated to be worth between $200,000 and $300,000.

As for Tupac’s love letters, the collection includes 22 autographed notes written by the rapper when he was just 16 years old. The West Coast legend addressed the letters to his high school sweetheart — Kathy Low — who also studied with him at the Baltimore School for the Arts. The letters could go for $60,000 to $80,000.

Along with Tupac and Biggie’s artifacts, the auction is expected to include other hip hop keepsake items and treasures such as photos, jewelry, luxury goods, flyers and posters, artwork and more.

Part of the auctions’ proceeds will benefit the Queens Public Library Foundation’s Hip-Hop Programs and Building Beats, which offer educational programs for underserved youth and teach entrepreneurial, tech, music and leadership skills. The auction is set for Sept. 15.