Coulombs law was first observed in 600 BC by Greek philosopher Thales of Miletus. if two bodies are charged with static electricity, they will either repulse or attract each other depending upon the nature of their charge. This was just an observation but he did not establish any mathematical relation for measuring the attraction or repulsion force between charged bodies.
After many centuries, in 1785, Charles Augustin de Coulomb who is a French physicist published the actual mathematical relation between two electrically charged bodies and derived an equation for repulsion or attraction force between them. This fundamental relation is most popularly known as Coulomb’s law.