A rare love letter written by Napoleon Bonaparte to Josephine, Viscomtesse de Beauharnais, his future wife, fetched more than five times its estimated price when it sold for 276,000 pounds ($552,000) at auction in London.

The letter is one of only three known correspondences from Napoleon to Josephine before they were married. It had been estimated to fetch a maximum of 50,000 pounds.

The letter was sold on Tuesday as part of a collection, which includes 570 hand-written manuscripts by notable figures of European history including Lord Byron, Elizabeth I, Sir Isaac Newton, Einstein, Churchill, Oliver Cromwell, Oscar Wilde and even Martin Luther — at Christie’s auction house in London.

The personal and private collection was assembled over 30 years by the late Albin Schram, an Austrian banker who kept the precious documents in the drawers of a filing cabinet in his home.

Schram was born to Austrian parents in Prague in 1926. He was conscripted into the German Wehrmacht, wounded and captured towards the end of World War II and taken to a prisoner of war camp in Kaliningrad, Russia, from where he escaped in the summer of 1945.

In later life, he devoted himself to private studies in legal history, and began collecting autographed letters.