SEASON 1 - SEASON 6
Len Goodman, Arlene Phillips, Bruno Tonioli & Craig Revel Horwood
The Originals: Craig, Arlene, Len and Bruno kicked things off in 2004
Strictly Come Dancing burst onto screens 16 seasons ago, in 2004.
The original line-up featured Bruno Tonioli and Craig Revel Horwood, both of whom are still on the panel in its current form.
The two long-standing stars were joined by original head judge Len Goodman.
The trio of dance pros were joined by Arlene Phillips, through to 2008, which marked Arlene's final season.
SEASON 7 - SEASON 9
Len Goodman, Alesha Dixon, Bruno Tonioli & Craig Revel Horwood
Controversy: Arlene was out and Alesha was in for Strictly 2009 - 2011
Having taken part on the series as a celebrity contestant, Alesha Dixon joined the panel in the first Strictly shake-up.
Arlene was given the boot, after six seasons, with the BBC stating that the show needed a refresh.
This decision courted controversy at the time, with fans accusing the BBC of discrimination against older women on television; the BBC, however, strongly denied this.
Alesha had appeared on season 5 of Strictly and had won it, with dance partner Matthew Cutler.
Guest Judge: Jennifer Grey
Stand in: Dirty Dancing's Jennifer Grey filled in for one week in 2011
Head judge Len had to sit a week out and was replaced with Jennifer Grey - star of Dirty Dancing.
Jennifer was the winner of the 11th season of Strictly's US counterpart Dancing With The Stars.
In Len's absence, Craig was head judge.
SEASON 10 - SEASON 14