Representing the UK in 1972 were The New Seekers with the song Beg, Steal Or Borrow.
Up against 17 other countries, they were respectable runners-up to Luxembourg's Vicky Leandross, whose song Apres Toi garnered 128 points to the UK's 114.
Here are some highlights from the event in Edinburgh.
5. UK entry
The new seekers sang Beg, Steal or Borrow, and landed the UK in second place.
Each country had two jury members, one aged between 16 and 25, the other between 26 and 55, who awarded between 1 to 5 points each for each performance, excluding their own country's performance.
7. How the castle got involved
The interval act for the 1972 contest was performed outside the vast Esplanade of the Great Hall of Edinburgh Castle.
The Irish entry, Sandie Jones, sung Ceol An Ghra in the Irish language, and according to the Eurovision website, it remains until now the only song ever sung in Irish in the history of the song contest.