By Michael Osborn
Entertainment reporter, BBC News
Peggy's time on Albert Square has featured moments of drama and joy
Actress Barbara Windsor has announced that she is leaving EastEnders after playing Peggy Mitchell for 15 years.
Here are some of the elements that have made the Albert Square matriarch so memorable to viewers.
GET OUTTA MY PUB!
Peggy Mitchell is best known as the landlady of the Queen Vic, which is at the hub of Albert Square life.
But she hasn't always been a fixture behind the bar. In 2001, she was forced to sell her beloved boozer after Frank Butcher left her penniless and it took years to wrestle it back.
The Queen Vic under Peggy's ownership has been at the centre of countless Walford dramas.
But she has the ultimate say over who's welcome and who's not, thanks to her inimitable catchphrase: "Get outta my pub!"
MOTHER OF THE BROOD
Peggy is the power behind the bar at the Queen Vic, but also rules the roost in the pub's family quarters.
Thuggish sons Phil and Grant are her pride and joy, but have caused their mother pain over the years. She dotes on daughter Sam, who is also a source of trouble.
In more recent years the Mitchell clan has expanded, with grandson Ben and blonde bombshell nieces Roxie and Ronnie inhabiting Peggy's kitchen and giving her more to worry about.
And then there's poor Billy, on the periphery of the family - dismissed as a waste of space and welcomed into the fold when it suits Peggy.
Peggy's romantic liaisons have been dramatic - thanks to her bad choices of men.
She married Frank Butcher in 1999 and it eventually emerged that he still held a candle for former wife Pat Evans.
Poor Peggy eventually discovered they were having an affair, leading to a memorable moment when she confronted the errant pair in the Queen Vic in front of all her regulars.
More recently, she was wooed by suave brother-in-law Archie Mitchell, who wielded increasing control over Peggy - a previously unthinkable feat.
After they had married, she discovered that Archie harboured a series of dark secrets.
PEGGY VS PAT
Peggy Mitchell and Pat Evans have lurched from being sworn enemies to best friends down the years.
The source of their ill feeling was Frank Butcher, who they both loved - sometimes at the same time.
In 1998, they were pitched against each other in a dramatic outing all of their own, in which accusations and slaps flew.
But in a recent episode, the pair joined forces to rush pregnant Heather to hospital in a stolen ice-cream van, and after getting inebriated declared they'd travel the world together.
One of Peggy's earliest hard-hitting storylines was a diagnosis of breast cancer and her treatment, which she underwent largely in secret.
The disease later returned and Peggy had a mastectomy.
More recently, she collapsed when campaigning hard to become a local councillor on the back of a crusade against Albert Square's massage parlour.