It was in 1799 that the meter became the official unit of length in France, but it was only in 1812 that the foot, or "pied metrique", was officially defined as one third of a meter, which made the French foot equivalent to 33,33 cm. Before that, the French foot equalled 32,48 cm so, if Napoleon was 5’2, that equalled 1,69 m or 5’6 in English/US feet as your foot unit equals "only" 30,48 cm. You knew that, right?