In May 1798, General Napoleon left for a campaign in Egypt. The French needed to threaten British India and the French Directory was concerned that Napoleon would take control of France. The French Army under Napoleon won an overwhelming victory in the Battle of Pyramids. Barely 300 French soldiers died, while thousands of Mamluks (an old power in the Middle East) were killed. But his army was weakened by bubonic plague and poor supplies because the Navy was defeated at the Battle of the Nile. The Egyptian campaign was a military failure but a cultural success. The Rosetta Stone was found by French engineer Captain Pierre-François Bouchard, and French scholar Jean-François Champollion was able to read the words in the stone. Napoleon went back to France because of a change in the French government. Some believe that Napoleon should not have left his soldiers in Egypt. Napoleon helped lead the Brumaire coup d'état of November 1799.