The United Kingdom did not intend to participate in the inaugural Eurovision Song Contest. Instead, they opted to take part in their own song contest called the Festival Of British Popular Songs.
In the following year in 1957, however, elements of the British song contest were incorporated into the Eurovision Song Contest.
[Source]
'Shining a light on the United Kingdom: 60 Years at Eurovision,' Eurovision.tv..
For the first 10 years of the Eurovision Song Contest, France placed in the top five. However, no one knows the real rankings of the first Eurovision, so every nation aside from the winner was given second place.
The subsequent rankings are as followed:
Paule Desjardins took home second place in 1957 for the song 'La Belle Amour.'
'Dors Mon Amour' by André Claveau won the 1958 contest.
Jean Philippe's 'Oui, Oui, Oui, Oui' won third place in 1959.
1960 saw another victory for France thanks to Jacqueline Boyer's 'Tom Pillibi.'
'Printemps (avril Carillonne)' by Jean-Paul Mauric took fourth place in 1961.
In 1962, France won the contest once more with 'Un Premier Amour' by Isabelle Aubret.
'Elle était Si Jolie' by Alain Barrière gave the nation its worst score yet in 1963 when it earned fifth place.
Rachel's 'Le Chant De Mallory' won fourth place in 1964.
Finally, in 1965, 'N'avoue Jamais' by Guy Mardel placed 3rd.
For nine years, Denmark placed within the top ten of the final rankings. However, after all those years of success, Denmark lost its stride in 1966 by placing 14th.
Denmark first took part in Eurovision in 1957, and their nine year reign lasted from their induction until 1966.
The longest kiss in Eurovision history occured in 1957 when the rule against having duos compete was lifted. Birthe Wilke and Gustav Winckler, the Danish entry who sang "Skibet Skal Sejle I Nat," kissed for a total of 12 seconds at the end of their song. The duo ended up placing third overall.
[Sources]:
Frankfurt 1957, Eurovision.tv.
Frankfurt 1957 Participants: Birthe Wilke and Gustav Winckler, Eurovision.tv.
Grand Prix Eurovision 1957 (Full Show from HR) 41:23-41:35, YouTube.com.
The Italian entry for the 1957 Eurovision Song Contest is the longest song in the history of the contest. "Corde Della Mia Chitarra" by Nunzio Gallo was five minutes and nine seconds in length.
Prior to this, it was only a suggestion that songs shouldn't exceed three minutes. For this reason, despite much protest, the song was not disqualified.
This did, however, lead to the official rule change mandating that songs must be no more than three minutes long.
[Sources]:
Frankfurt 1957, Eurovision.tv.
Participants of Frankfurt 1957: Nunzio Gallo, Eurovision.tv.
Rules of the Eurovision Song Contest, Eurovision.tv.