The Doctor Who missing episodes are the many instalments of the long-running British science fiction television programme Doctor Who that are missing, with no known film or videotape copies existing. They were wiped by the BBC during the 1960s and 1970s for a variety of economic and space-saving reasons. In all, there are 27 serials that do not exist in complete form in the BBC's archives, because 108 of 253 episodes produced during the first six years of the programme are missing. Many more were thought to have been so in the past before episodes were recovered from a variety of sources, most notably overseas broadcasters. Doctor Who is not unique in this respect, as thousands of hours of programming from across all genres were destroyed up until 1978, when the BBC's archiving policies were changed. Unlike other series, Doctor Who is unique in having all of its missing episodes surviving in audio form, recorded off-air by fans at home. Additionally, every 1970s episode exists in some form, which is not the case for several other series. Efforts to locate missing episodes continue, both by the BBC and by fans of the series. Extensive restoration has been carried out on many surviving and recovered 1960s and 1970s episodes for release on VHS and more recently on DVD. The surviving soundtracks of missing episodes have been released on cassette and more recently CD. Both fan groups and the BBC have released reconstructions of missing episodes, matching photographs from the episodes with the soundtracks.

http://en.wikipedia.org/wiki/Doctor_Who_missing_episodes

John Milton published Areopagitica, arguing for the right to free speech and against publication censorship during the English Civil War.
(http://en.wikipedia.org/wiki/Areopagitica)

The Manchester Martyrs were hanged in Manchester, England for their rescue of two Irish nationalists, who played important roles in the failed Fenian Rising, from jail.
(http://en.wikipedia.org/wiki/Manchester_Martyrs)

The BBC television series Doctor Who premiered with William Hartnell in the titular role.
(http://en.wikipedia.org/wiki/Doctor_Who)

The People's Republic of China was given China's permanent seat on the United Nations Security Council.
(http://en.wikipedia.org/wiki/China_and_the_United_Nations)

Omar Rezaq and two others from the Abu Nidal terrorist group hijacked EgyptAir Flight 648 over the Mediterranean Sea.
(http://en.wikipedia.org/wiki/Abu_Nidal)

kismet   (n)       Fate; a predetermined or unavoidable destiny.
(http://en.wiktionary.org/wiki/kismet)

History would be an excellent thing if only it were true.
--Leo Tolstoy
(http://en.wikiquote.org/wiki/Leo_Tolstoy)