These are some of the most important authors who contributed significantly on the modern theory of Information Visualisation.
Johann Heinrich Lambert [1728-1777]
Johann Heinrich Lambert and William Playfair are considered the inventors of the modern graph design as they were the first in introducing graphics, in contrast with the tabular presentation of data. Johann Heinrich Lambert was a famous mathematician who developed Demoivre's theorem on trigonometry and non-Euclidean geometry.
See a description of J. H. Lambert on Wikipedia:Johann_Heinrich_Lambert
William Playfair [1759-1823]
W. Playfair was a Scottish engineer and political economist, he was an important inventor of statistical graphics.
See a description of W. Playfair on Wikipedia:William_Playfair
Jacques Bertin [1918 - ]
Bertin, a French cartographer, was the first who tried in 1967 to defining a theory of Information Visualization by the identification of the basic elements of diagrams and described a framework for the design.
Edward Tufte [1942 - ]
E. Tufte is one of the biggest expert in the presentation of informational graphics. He published in 1983 his theory of data graphics centred on the maximisation of the density of useful information in graphics
See a description of E. Tufte on Wikipedia:Edward_Tufte