De Forest
De Forest was granted a patent for his early two-electrode version of the Audion on November 13, 1906 (), and the "triode" (three-electrode) version was patented in 1908 (). De Forest continued to claim that he developed the Audion independently from John Ambrose Fleming's earlier research on the thermionic valve (for which Fleming received Great Britain patent 24850 and the American Fleming valve patent ), and De Forest became embroiled in many radio-related patent disputes. De Forest was famous for saying that he "didn't know why it worked, it just did".