Episode 7 follows the most recent full decade of the Christmas number one battles: the 2010s.

The decade saw The X Factor continue where it left off in the 2000s, undeterred by the Rage Against the Machine battle of 2009.

Elsewhere, the 2010s saw the return of the charity record, with five of the 10 number ones raising funds and awareness for various causes.

The decade also saw the arrival of streaming in the charts, leading to a huge surge in Christmas favourites every year.

Full Christmas number ones (look away if you don’t want ‘spoilers’!):

• 2010: Matt Cardle – ‘When We Collide’
• 2011: Military Wives – ‘Wherever You Are’
• 2012: The Justice Collective – ‘He Ain’t Heavy He’s My Brother’
• 2013: Sam Bailey – ‘Skyscraper’
• 2014: Ben Haenow – ‘Something I Need’
• 2015: Lewisham & Greenwich NHS Choir – ‘A Bridge Over You’
• 2016: Clean Bandit, Sean Paul and Anne-Marie – ‘Rockabye’
• 2017: Ed Sheeran – ‘Perfect’
• 2018: LadBaby – ‘We Built This City’
• 2019: LadBaby – ‘I Love Sausage Rolls’

Episode 6 travels back to the Christmas number ones of the 2000s, a decade dominated by talent shows and reality TV.

After Girls Aloud took on One True Voice in 2002, Simon Cowell saw gold and took over the festive chart for the second half of the decade with his next show The X Factor.

However, this led to one of the biggest chart shocks of all time, when a certain Facebook campaign took the most unlikely artist to the summit by the end of the decade.

Elsewhere, there was yet another Band Aid, an ’80s piano cover and a kids TV show legend.

Full Christmas number ones (look away if you don’t want ‘spoilers’!):

• 2000: Bob the Builder – ‘Can We Fix It?’
• 2001: Robbie Williams & Nicole Kidman – ‘Somethin’ Stupid’
• 2002: Girls Aloud – ‘Sound of the Underground’
• 2003: Gary Jules & Michael Andrews – ‘Mad World’
• 2004: Band Aid 20 – ‘Do They Know It’s Christmas’
• 2005: Shayne Ward – ‘That’s My Goal’
• 2006: Leona Lewis – ‘A Moment Like This’
• 2007: Leon Jackson – ‘When You Believe’
• 2008: Alexandra Burke – ‘Hallelujah’
• 2009: Rage Against the Machine – ‘Killing in the Name’

Episode 5 is a trip back to the Christmas number ones of the 1990s, the decade of Girl Power and power ballads.

Cliff Richard was still around, we said goodbye to a rock icon, Take That were beaten by a bloke in a rubber suit, and the Spice Girls repeated the Beatles’ record.

Novelty was back in the form of Mr Blobby, Teletubbies and South Park’s Chef.

Plus it was the decade that saw festive favourites by Mariah Carey and East 17. But that was about it. And they were in the same year!

Full Christmas number ones (look away if you don’t want ‘spoilers’!):

• 1990: Cliff Richard – ‘Saviour’s Day’
• 1991: Queen – ‘Bohemian Rhapsody/These Are the Days of Our Lives’
• 1992: Whitney Houston – ‘I Will Always Love You’
• 1993: Mr Blobby – ‘Mr Blobby’
• 1994: East 17 – ‘Stay Another Day’
• 1995: Michael Jackson – ‘Earth Song’
• 1996: Spice Girls – ‘2 Become 1’
• 1997: Spice Girls – ‘Too Much’
• 1998: Spice Girls – ‘Goodbye’
• 1999: Westlife – ‘I Have a Dream/Seasons in the Sun’

Episode 4 takes us back to the 1980s, the era of charity singles, random one-offs and iconic festive records.

The decade continued where the ’70s left off, with novelty and one-off successes for grandmas, Italian lovers and a random ’50s re-release.

There are also Christmas classics for years to come for Wham, The Pogues, Shakin’ Stevens, Cliff Richard and the charity behemoth of Band Aid.

Full Christmas number ones (look away if you don’t want ‘spoilers’!):

• 1980: St Winifred’s School Choir – ‘There’s No One Quite Like Grandma’
• 1981: The Human League – ‘Don’t You Want Me’
• 1982: Renee & Renato – ‘Save Your Love’
• 1983: The Flying Pickets – ‘Only You’
• 1984: Band Aid – ‘Do They Know it’s Christmas’
• 1985: Shakin’ Stevens – ‘Merry Christmas Everyone’
• 1986: Jackie Wilson – ‘Reet Petite’
• 1987: Pet Shop Boys – ‘Always on My Mind’
• 1988: Cliff Richard – ‘Mistletoe & Wine’
• 1989: Band Aid II – ‘Do They Know It’s Christmas’

Episode 3 looks back at the golden era of the Christmas number one: the 1970s.

Arguably the decade where the UK’s fascination with the festive chart toppers truly began, it was the decade of glam rock, novelty fun and Christmas anthems.

Slade, Mud, Wizzard, Johnny Mathis and Boney M would show how to make a great Christmas song that can stand the test of time, and the charts become flooded with festive hits: some classic, some… not so classic.

Benny Hill and Little Jimmy Osmond bring novelty to the top, and there are truly huge chart hits for Queen and Wings.

Full Christmas number ones (look away if you don’t want ‘spoilers’!):

• 1970: Dave Edmunds – ‘I Hear You Knocking’
• 1971: Benny Hill – ‘Ernie (The Fastest Milkman in the West)’
• 1972: Little Jimmy Osmond – ‘Long Haired Lover from Liverpool’
• 1973: Slade – ‘Merry Xmas Everybody’
• 1974: Mud – ‘Lonely This Christmas’
• 1975: Queen – ‘Bohemian Rhapsody’
• 1976: Johnny Mathis – ‘When a Child is Born’
• 1977: Wings – ‘Mull of Kintyre’
• 1978: Boney M – ‘Mary’s Boy Child/O My Lord’
• 1979: Pink Floyd – ‘Another Brick in the Wall’

For episode 2, we travel back for the Christmas number ones of the 1960s.

It was the decade of the Beatles’ takeover of the festive charts, plus a couple of oddities and rock and roll favourites.

It proved to be the decade that showed that the festive chart was something the biggest artists around battled out for, with big hits for Cliff Richard, Elvis Presley and Tom Jones.

Full Christmas number ones (look away if you don’t want ‘spoilers’!):

• 1960: Cliff Richard & The Shadows – ‘I Love You’
• 1961: Danny Williams – ‘Moon River’
• 1962: Elvis Presley – ‘Return to Sender’
• 1963: The Beatles – ‘I Want to Hold Your Hand’
• 1964: The Beatles – ‘I Feel Fine’
• 1965: The Beatles – ‘Day Tripper/We Can Work It Out’
• 1966: Tom Jones – ‘The Green Green Grass of Home’
• 1967: The Beatles – ‘Hello Goodbye’
• 1968: The Scaffold – ‘Lily the Pink’
• 1969: Rolf Harris – ‘Two Little Boys’

For episode 1, we go back to where it all began: 1952.

We first take a look at what came before the UK Singles Chart began, and the Christmas standards we still hear today such as Bing Crosby’s ‘White Christmas’ and ‘Let It Snow’.

While the Christmas number one concept didn’t exist for a while yet, the 1950s was the decade of mellow ballads, piano party tunes, and the emergence of rock and roll.

Full Christmas number ones (look away if you don’t want ‘spoilers’!):

• 1952: Al Martino – ‘Here In My Heart’
• 1953: Frankie Laine – ‘Answer Me’
• 1954: Winifred Atwell – ‘Let’s Have Another Party’
• 1955: Dickie Valentine – ‘Christmas Alphabet’
• 1956: Johnnie Ray – ‘Just Walkin’ in the Rain’
• 1957: Harry Belafonte – ‘Mary’s Boy Child’
• 1958: Conway Twitty – ‘It’s Only Make Believe’
• 1959: Emile Ford and the Checkmates – ‘What Do You Want to Make Those Eyes At For?’