NEW YORK (AP) — An ornate gold medal depicting an eagle, commissioned by George Washington as a symbol of the ideals of the Revolutionary War and later presented to the Marquis de Lafayette, is to be sold at auction later this year.

Sotheby's auction house made the announcement Thursday, on the 250th anniversary of the birth of Lafayette. The gold and enamel medal — showing an eagle surrounded by a laurel wreath — is estimated to bring up to $10 million (euro7.32 million) at the Dec. 11 sale, it said.

After Washington's death, the medal was presented to Lafayette by Washington's family; it was consigned to the auction by Lafayette's great-great granddaughter, Baronne Meunier du Houssoy, of France.

"This medal is a treasure from the age of heroes; one of those magical artifacts that burns through time and transports us to a moment that changed the world forever,'' David Redden, vice chairman of Sotheby's, said in a statement. "Not only is it a precious and unique work of art, but a link between two men who, against the most improbable odds, managed to change the course of history.''

Washington, Lafayette and several other commanders formed The Society of the Cincinnati in 1793 to uphold the values of the Revolution.

Members were presented with eagle medals, but the one made for Washington differed from the rest. Washington asked Pierre Charles L'Enfant, who served under him in the Continental Army and was the engineer and designer of Washington, D.C., to design one "finished in a masterly manner (and) ornamented in an elegant, tho' not costly Stile,'' based on his specifications.

Sotheby's said Lafayette treasured the medal from his hero, even wearing it while having his portrait taken during a trip to Charleston, South Carolina. The portrait now hangs in the Gibbes Museum of Art in Charleston.

The medal, which contains the Latin inscription "he left everything to serve the republic,'' was last seen publicly at the Chicago World's Fair in 1893. It is being offered for sale in what is believed to be its original red leather presentation box bearing the label, Washington's Cincinnati Badge.

Washington had considerable admiration and affection for Lafayette, treating him as the son he never had. Lafayette joined the American Revolution after leaving the French Army at age 19. He played a pivotal role in the final victory at the Battle of Yorktown in 1781.