<P> James Clerk Maxwell FRS FRSE ( / ˈmækswɛl / ; 13 June 1831 -- 5 November 1879 ) was a Scottish scientist in the field of mathematical physics . His most notable achievement was to formulate the classical theory of electromagnetic radiation , bringing together for the first time electricity , magnetism , and light as different manifestations of the same phenomenon . Maxwell 's equations for electromagnetism have been called the `` second great unification in physics '' after the first one realised by Isaac Newton . </P>
who was the first person to suggest that light is an electromagnetic wave
James Clerk Maxwell