Officially, the first successful sustained powered flights in a heavier-than-air machine were made by Wilbur and Orville Wright on December 17, 1903. In fact their Kitty Hawk had to start from a catapult (pulled by weights) against a strong headwind and fly
down the 90 foot high “Kill Devil Hill”. They only flew the distance of 40 metres.
The German civil servant Karl Jatho flew a heavier-than-air machine near Hannover, starting on level ground in perfectly calm weather (August 18th 1903 - three months before
the Wright brothers). Some weeks after that (and still before Wilbur & Orville’s flight) he flew his plane over a distance of 60 metres, 33% further than the Wrights. Here are pictures of his plane.
Even earlier, on August 14th 1901, the German Emigrant to the U.S., Gustav Whitehead alias Weißkopf, managed to fly 800m with his “No 21” in Connecticut. In 1996, a replica of this plane was built in Germany and it flew very well. Some pictures of him and his plane here. You can read the whole story on the official website www.weisskopf.de in German and (bad) English. This once more shows that history is made and doesn’t just happen.
That is why we need historians. :-)