A longstanding mystery surrounding the deaths of 3,000 soldiers from Napoleon’s army found in a mass grave in Lithuania has been solved.

The jumbled bones of the men who died on the French leader’s ill fated attempt to march on Moscow in 1812 show signs of starvation, according to archaeologists from the University of Central Florida.

According to Forbes, buttons found on the site, which was first discovered in Lithuanian capital Vilnius in 2002, show over 40 different regiments were represented from Napoleon’s army as they made their desperate dash back across Europe.

Around 500,000 in the Emperor’s army began their long march to Moscow in June 1812, but by the time they were stumbling back to Vilnius in retreat six months later only 40,000 had survived.

Around 20,000 men were believed to have died of hypothermia, starvation and typhus in Vilnius alone.