Though the practice of mapmaking is thousands of years old, modern enhanced data visualization, particularly through the use of time-series and data maps, really began in the 18th century with Johann H. Lambert, a Swiss mathematician, and William Playfair, a Scottish engineer and political economist, both of whom are featured in Tufte’s book as pioneers in visualization. In this video, we also learn about what Tufte considered one of the greatest graphics of all time – Charles Joseph Minard’s visualization of how the size of Napoleon’s army changed as it marched east towards Moscow and then returned during a brutally cold winter.