Sir William Herschel discovered Uranus in 1781, the first ever recorded discovery of a planet (the first six planets, from Mercrury to Saturn, had been known since antiquity). As the planet's discoverer, Herschel was given the responsibility of naming his new planet. He choose to honor King George III by calling the planet "Georgium Sidus" which translates to "George's Star".
Although the name Georgium Sidus was adopted and used in England through the middle of the 19th century, it was never adopted by the world at large. A French astronomer proposed naming the planet "Herschel", but it was the German astronomer Johann Bode who decided to call the planet "Uranus"; a name which was quickly accepted by the scientific community.