Democritus lived and worked in Abdera in Thrace from about 460 B.C. to 370 B.C. He also traveled a great deal to places, such as Babylon, Egypt, Ethiopia, India and Greece.
Democritus is also said to have known Hippocrates, Socrates, Plato, Leucippus and Anaxagoras, and traveled to visit or work with these philosophers. Although he was wealthy, he preferred to spend his money on travel and furthering his studies.
Democritus is a well-known Greek philosopher, and his studies centered around the theory of the atom. His theory was that everything is made up atoms, and atoms are so small that they cannot be seen.