Between 1951 and 1987, Von Karajan recorded the whole Beethoven cycle five times, of which four times with the Berlin Philharmonic. This is part of the second cycle, from the 60s. It is by most seen as the pinnacle of Beethoven interpretations, and the height of power of both conductor, orchestra and recording technique. Personally I find it difficult to relate to those enormous claims, but I do admit it is a reference.
How powerful this symphony must have felt to the people that first heard it. This, the probably best known four notes in all of classical music, must have been a thunderous experience. In a world without radio, where music was limited to someone playing a few tunes in your local bar, what a life changing event it must have been to hear this the first time.