Although a man named Johhanes Kelper did one of the first documented studies of tessellations when he wrote about the regular and semiregular tessellations In 1619. E. S. Fedorov's work on tessellations marked the unofficial study of tessellations in math about two hundred years later.
One of the most famous contributors was M. C. Escher. A dutch artist who greatly respected math mathematicians, yet he had no training in math or science. He is famous for Ascending and Descending, Relativity, his Transformation Prints, such as Metamorphosis I, Metamorphosis II and Metamorphosis III, Sky & Water I or Reptiles. (Some of Escher's work is below this paragraph).
Beleive it or not, but tessellations actually came up before Johhanes Kelper. In 14th century Spain, Alhambra tiling was a beautiful art forming many different geometrical shapes. Some of these were not real tessellations, because they had gaps and did not form consistant patterns, but many were true tessellations!!!
A picture of Alhambra tiling