
It's hard to believe that two decades have gone by since Girls Aloud were formed on British reality TV show, Popstars: The Rivals, becoming one of the biggest girl groups of all time.
The five-piece act made up of Cheryl (she goes by just Cheryl now after divorcing from her husband Ashley Cole], Nicola Roberts, Nadine Coyle, Kimberley Walsh, and the late Sarah Harding had to battle it out against a rival boy band, One True Voice, for the Christmas number one.
In the end, the Girls Aloud song 'Sound of the Underground' easily beat their male rivals to the top of the charts.
Watch: Breast cancer anthem 'I Touch Myself'. Story continues below.
In a recent interview with BBC News, Kimberley Walsh said that 'Sound of the Underground' was a life-changing song for the band.
"We knew we had hit gold when we heard it for the first time," Kimberley told the BBC.
"It's amazing. It was our first single 20 years ago, and it's still one of our most popular and most played songs. We're all very proud of it and it means a great deal to us."