This gallery example recreates Charles Joseph Minard’s classic flow map of Napoleon’s 1812 Russian campaign, showing the shrinking size of the French army through a series of colored bands that advance toward Moscow and later retreat. The visualization uses d3.csvParse to load embedded troop, city, and river data, then renders the troop paths with d3.area() and curveCatmullRom, while d3.group() separates the data by army group and direction. Animated hover interactions trigger tooltips with survivor counts, and CSS transitions highlight the selected path.