John Henry `` Bonzo '' Bonham ( May 31 1948 â `` September 25 , 1980 ) was an English rock drummer . He was best known for being a member of London hard rock band Led Zeppelin . John Henry Bonham ( 31 May 1948 â `` 25 September 1980 ) was a British musician and songwriter , best known as the drummer of Led Zeppelin .