The frail Napoleon knew he was near his end as he penned his will, a document that requested his ashes be scattered along the Seine river's banks.

On Wednesday, the only known copy of this testament is being sold by Paris' Drouot Auction house.

Pierre Gheno, an expert on the French emperor and military legend, said the will's copy is "very special in the great mass of documents produced in Napoleon's era."

The 51-year-old Napoleon died in 1821 in exile on Saint Helena island, 19 days after penning the will.

The original is in France's national archives. The copy, written by a close adviser, is expected to fetch 120,000 euros ($162,000).

The fallen emperor's ashes weren't exactly scattered along the Seine, but rather transferred to Paris' Invalides monument in 1840.