I would never thought to ask this question but I came across the answer this morning.
William Playfair (22 September 1759 – 11 February 1823), commonly known as a Scottish engineer and political economist, served as a secret agent on behalf of Great Britain during its war with France. The founder of graphical methods of statistics, Playfair invented several types of diagrams: in 1786 the line, area and bar chart of economic data, and in 1801 the pie chart and circle graph, used to show part-whole relations. As secret agent, Playfair reported on the French Revolution and organized a clandestine counterfeiting operation in 1793 to collapse the French currency.
The Scottish Scoundrel Who Changed How We See Data - Atlas Obscura
After he left home in his late teens, Playfair headed to England to apprentice with the engineer James Watt, whose streamlined steam engine design would soon kickstart the Industrial Revolution. He served as Watt’s draughtsman and clerk, copying complex drawings of his new inventions. Watt was a demanding and critical boss—“I must warn you that Playfair is a blunderer,” he wrote to his business partner, Matthew Boulton, soon after hiring him—but Playfair loved him, later calling him a “natural genius” who “in remote antiquity, would have been deified amongst the inventors of the arts of life.” Under his watchful eye, Playfair honed the artistic precision he later brought to data illustration.