Two of the premier inventors working on this were Louis Daguerre of France and Henry Fox Talbot of England. In 1835, Talbot, independently of any work Daguerre or his partners had completed, developed a method that involved silver chloride on paper which captured an image briefly until being exposed to daylight.
Unbeknownst to Talbot, Daguerre's late partner had discovered the same technique 20 years earlier but had scrapped the idea because the images weren't sustainable. Talbot did not make his discovery public, and when Daguerre announced a patent for a working camera, Talbot released an open letter stating he had invented it first.
However, Daguerre's process was much different than Talbot's, and Daguerre filed for a patent in Britain as well.
Days later, France announced they were gifting the invention to the rest of the world for free, but because the patent was already filed, everyone in Britain had to have a license!
