His relation equates Planck's constant over momentum to the wavelength of a matter wave.  
His books have been translated as Matter and Light and Revolution in Physics.  He was so impressed by his brother Maurice's work on the nature of radiation that he changed his career from history to physics.  His doctoral thesis, ignored due to lack of light-wavelength-comparable instrumentation, was recognized by Einstein, and later confirmed by electron diffraction studies.  His relation equates Planck's constant over momentum to the wavelength of a matter wave.  First noting that wave-particle nature of radiation applies to matter, FTP, name this Frenchman who won the 1929 Nobel Prize.
His books have been translated as Matter and Light and Revolution in Physics.  
Louis Victor de Broglie