The BBC One soap will give fans the opportunity to go back in time and watch the first episode on BBC iPlayer and the Red Button from Monday 16 February.
In the first ever visit to Albert Square, fans will meet a very young Ian Beale and Sharon Watts in the 1985 episode.
Also, the fate of missing resident Reg Cox is revealed to Den, Arthur and Ali when they all break into his flat and Dr Legg is quickly called to the scene. And, Pauline and Arthur reveal a secret to Lou, while Nick Cotton causes trouble in the Queen Vic.
EastEnders' much talked-about live anniversary week will air from Monday 16 until Friday 20 February on BBC One.
It's set to be an "explosive week of drama, special shows and a flashback episode" with shocking revelations and twists as Lucy Beale's killer is finally revealed.
There will be a series of live elements in all episodes that week and a fully live half hour episode on Friday night at 8pm.
The live week will also see the return of some of EastEnders' most iconic characters. Barbara Windsor will reprise her role as Peggy Mitchell for one episode, while Jo Joyner and John Partridge will also reprise their roles as Tanya Cross and Christian Clarke.
Viewers will also see Hetti Bywater (Lucy Beale), Tanya Franks (Rainie Cross) and Jamie Lomas (Jake Stone) back for the flashback episode.
BBC controller Charlotte Moore said: "Alongside the unmissable drama, we have a Graham Norton special and Zoe Ball will present a live backstage show with Ore Oduba and Joe Swash to complete proceedings - it's going to be off the scale!"
Joining Graham Norton on his show will be past and present cast members including June Brown, Pam St Clement, Adam Woodyatt, Letitia Dean, Kellie Bright, John Altman, Richard Blackwood, Jessie Wallace, Shane Richie and Danny Dyer.
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