To read the chart, you should know that Napoleon's Grande Armée starts out as the wide, brown line on the left. 422,000 men crossed the Niemen River to begin the campaign. The Army is marching to the east, left-to-right. As the Army progresses further, soldiers die and the size of the force is reduced, indicated by the diminishing width of the brown line.
You'll also see where two splinter forces leave the main body to cover the supply lines and any possible retreat.
Eventually, a reduced French force arrived in Moscow, which the Russians had abandoned. There was very little food in the city, and fires broke out over several days. Napoleon was forced to retreat, and 100,000 men started marching west (signified by the black column).
Losses continued in their retreat, even as they rejoined the forces left behind. The weather turned very cold (the chart on the bottom shows the temperatures during the retreat). The final column that returned to cross the Niemen River westbound was 4,000 men from Moscow and 6000 men from the units left to cover the retreat.
This was a battle of logistics as well as of tactics; the French Army lost more men to starvation, desertion, typhus, and suicide than to combat. The Army advanced faster than supply trains could manage, and there was no forage available.
Best Mashup of 2009Minard's chart tells this brutal story with elegance. Until recently, reproductions and redesigns of the information have been paper-based, but new work at Standford University has used a mashup of Google Maps and a visualization tool called ProtoVis to produce a digital presentation of Minard's chart.
The temperature scale presented uses the now obsolete Reaumur scale (°R), the same scale as Minard used.
Click here to see the chart in it's own webpage, where you can scroll, zoom in and out, and look at either Maps or Terrain. It's very well done, and conveys the efficiency of the original along with new tools.