Sir Rowland Hill, KCB, FRS was an English teacher, inventor and social reformer. He campaigned for a comprehensive reform of the postal system, based on the concept of Uniform Penny Post and his solution of prepayment, facilitating the safe, speedy and cheap transfer of letters. Hill later served as a government postal official, and he is usually credited with originating the basic concepts of the modern postal service, including the invention of the postage stamp.

https://en.wikipedia.org/wiki/Rowland_Hill