Santiago Ramón y Cajal (1 May 1852 – 17 October 1934) was a Spanish neuroscientist and pathologist, specializing in neuroanatomy, particularly the histology of the central nervous system. He won the Nobel prize in 1906, becoming the first person of Spanish origin who won a scientific Nobel prize. His original investigations of the microscopic structure of the brain made him a pioneer of modern neuroscience. Hundreds of his drawings illustrating the delicate arborizations of brain cells are still in use for educational and training purposes.
Source: Santiago Ramón y Cajal on Wikipedia (Wikipedia contributors, CC BY-SA 3.0)