The map shows the (approximate) position of Napoleon's army as it invades and retreats from Russia in the 1812 campaign; the width of the lines show the size of the army as it dwindles from a maximum of 340,000 to an end value of 4,000. No scale is displayed for concision. Data is taken from here and here
This is a reimplementation, not a reimagination, of Minard's diagram. The only significant addition is the temporal placement of elements. This helps clarify the most confusing elements of the original (such as the direction of the temperature graph). All animation timing is done by purely by D3 transitions. This frees up color from representing the army's direction: here the different branches of the French force each have their own color. Even these minor improvements can only mean, though, that this has now displaced Minard's original as greatest statistical graphic ever created. (Unless you really miss the original rivers, I guess.)
Click on the plot to restart the animation.