United Kingdom

Long before it became one of the Big Five, The United Kingdom was part of the First Ten and started its long and varied Eurovision journey in 1957's Frankfurt Contest (debuting alongside Austria and Denmark) with Patricia Bredin's All, ending the night in seventh place that night.  After skipping the 1958 Contest in Hilversum, the UK marched forward after their debut with three consecutive second-place finishes in 1959, 1960 and 1961, and followed up these initial successes with another two years of silvers in 1964 and 1965.  Then in 1967, Sandie Shaw's Puppet On a String brought the UK's first winner's trophy to London, which hosted the 1968 Contest where Cliff Richard again scored a second-place finish on home turf.  In 1969 Lulu hit the stage in Madrid with Boom Bang-a-Bang and brought the UK its second win, making the country a perennial favorite from that point forward.  Among the earlier contestants for UK was a young Olivia Newton John, who long before her Grease fame represented the country at the Brighton Contest in 1974 with Long Live Love (UK hosted after Luxembourg's consecutive wins began to cause financial issues for the national broadcaster RTL), battling against ABBA's Waterloo (the latter won that night, scoring Sweden's first gold at the Contest and launching their own globally successful career).

Though the 70s, 80s and 90s, it was rare to see the UK anywhere near the bottom of the score board (the language restriction of singing in your country's official language(s) obviously did not impact the UK and Ireland much, as English continued its ascent to be a global language).  In fact, the country took home the winner's trophy three more times (in 1976 with Brotherhood of Man's Save Your Kisses for Me in the Hague; in 1981 with Bucks Fizz's Making Your Mind Up in Dublin; and with Katrina and the Waves' Love Shine a Light in 1997 again in Dublin - the last winning UK song), garnered a total of fifteen second place finishes and three third placed entries (including the UK's last successful entry in the form of Jessica Garlick's Come Back in 2002's Talinn Contest).  Here's a clip of Brotherhood of Man live from The Hague stage in 1976:

Then began the UK's great decline at Eurovision, starting with Jemini's Cry Baby, scoring the country's first and only nul point at the Riga Contest in 2003.  In the decade that followed, the UK's early fortunes reversed and it became a rarity to see the country anywhere near the top of the scoreboard.  The only exception to this was Jade Ewen's 2009 entry It's My Time (written and composed by Andrew Lloyd Webber, who wanted to bring the UK back to its glory days) at the Moscow Contest, coming in fifth in a field of success dominated by Eastern European and Scandinavian acts.  After years of sending sub-par entries to Eurovision, the UK has recently been playing on a nostalgia experiment that started with Engelbert Humperdinck's Love Will Set You Free at last year's Baku Contest, with the song finishing in last place (with only 12 points total).  This year the vintage throw-back pattern continues with Bonnie Tyler's Believe In Me, which will be presented in the Final on May 18th in Malmo: