Hi, I discovered that a current carrying wire caused a compass needle to magnetize and deflect and create magnetic fields.
Andre Marie Ampere (1775-1836)
Meanwhile, I demonstrated the magnetic effect based on the direction of the current. I called this theory electrodynamics.
Michael Faraday (1791-1867)
I conducted induction experiment showing the effect of currents on magnets. I also discovered the principles of magnetic induction, diamagnetism, and the laws of electrolysis.
James Clerk Maxwell (1831-1879)
I predicted the connection of magnetism and electricity leading directly to the prediction of electromagnetic waves. I contributed in making equations about the relationship of electricity and magnetism.
Heinrich Hertz (1857-1894)
I showed evidence of electromagnetic wave and linked it to light. The discovery of electromagnetic waves led to the development of the radio.
Present Day
Ah! So that is how the electromagnetic theory was formed by the contributions of these scientists.