They wrote the song that is deemed by many to be the greatest rock song of all time, Stairway to Heaven. Over 8 minutes long, it changes tempo and style as it progresses, ending in hard rock complete with one of the greatest guitar solos of all time.
These guys, Jimmy Page and Robert Plant, they know how to rock.
They formed the band in the late 60's and became famous quickly for their intricate stylized performances. They didn't just have songs with distinct beginning and endings, they put on elaborately weaved together shows.
They knew who their audience was, they knew how to play to a crowd of people looking to expand their minds, and they kicked ass. They took psychedelic rock to the next level and beyond. They pushed the limits all around them. They filled arenas and toured the world. They outsold the Rolling Stones and other top bands of the time. They used lighting and effects to enhance the experience for their fans.
They disbanded in 1980 following the death of drummer John Bonham, but have played various reunion concerts and made special appearances together.
The legacy they left, though, will live on forever.