Green's Theorem is named after the self-taught English scientist George Green (1793-1841). He worked fulltime in his father's bakery from the age of nine and taught himself mathematics from library books. In 1828 he published privately An Essay on the Application of Mathematical Analysis to the Theories of Electricity and Magnetism, but only 100 copies were printed and most of those went to his friends.
This pamphlet contained a theorem that is equivalent to what we know as Green's Theorem, but it didn't become widely known at that time. Finally, at age 40, Green entered Cambrigde University as an undergraduate but died four years after graduation. In 1846 William Thompson (Lord Kelvin) located a copy of Green's essay, realized its significance, and had it reprinted.
Green was the first person to try to formulate a mathematical theory of electricity and magnetism. His work was the basis for the subsequent electromagnetic theories of Thomson, Stokes, Rayleigh and Maxwell.