Horizon is a current and long-running BBC popular science and philosophy documentary programme. Series one was broadcast in 1964 and as of July 2020 it is in its 56th series. Over 1,250 episodes have been broadcast (including specials) with an average of 23 episodes per series during the 56-year run. * 1964–1969 – 135 episodes * 1970–1979 – 299 episodes * 1980–1989 – 234 episodes * 1990–1999 – 220 episodes * 2000–2009 – 191 episodes * 2010–2019 – 167 episodes * Since 2020 – 14 episodes