[2] The serial originally focused on the Hart and Gates family and some of their friends and close associates living in the fictional outer London suburb of Charnham.
The Hart family consisted of builder Chris (Ian Ashpitel), his wife Annie (Liz Crowther) and their four children: ladies' man Duncan (Rocky Marshall); his twin sister, trainee solicitor and confused virgin Holly (Sandra Huggett); feisty Melanie, who became a police officer (Cordelia Bugeja); and schoolboy Jamie (Michael Cole).
After losing his wife Sally (Jean Heywood) in the opening episodes, Chris' father Angus (Ian Cullen) came to live with the family.
Annie's parents, staunchly conservative Elsa Gates (Delena Kidd) and philandering Jack (Kenneth Farrington), lived nearby.
Other original characters were Chris's partner in their building business, Nick Trip (Barry McCormick); Melanie's bubbly best friend Claire Toomey (Tina Hall); Annie's baby-obsessed friend Maria Simons (Annie Miles); and Duncan's loyal drinking partners Tim Webster (Idris Elba) and Roy Farmer (Miles Petit).
Pete, played by ex-Brookside actor David Easter, provided the series with a much-needed villain, and he quickly became the show's standout character.
Another early arrival was the sassy bisexual Susie Ross (Tina Landini), who took a job at The Lock and romanced both Duncan and his twin sister Holly.
Nick's troublesome teenage son Liam (Stephen Hoyle) arrived, and neighbourhood nosey parker Bill Cockerill (Roger Sloman) and his wife Samantha (Tessa Wyatt), along with their daughter Charlotte, made several appearances.
Also introduced was Dusty McHugh (Doreen Ingleton), the strident owner of the local mini supermarket, and her children, mouthy daughter Yasmin (Ebony Thomas) and conscientious son Benji (Junior Laniyan).
Clive's older brother Dudley (David Verrey), also known as Serge Pompidou, became the new chef at The Lock, and was soon joined there by vapid barmaid Siobhan Jones (Jemma Walker).
Elsa suffered amnesia during her subsequent recuperation, and Jack kept her isolated from family for fear that their support or inquiries could trigger the return of her memory and uncover the truth.
When Elsa's memory did begin to return, Jack smothered her with a pillow, changed his will to make Pete Callan his chief beneficiary, and committed suicide by gassing himself in his car.
In 2000, coinciding with the introduction of the Warrington family, the geographic focus of the series was retconned to Stanley Street, in the fictitious West London W15 postal district.
Previously, the specific location of Charnham had never been explicitly stated; it was known to be close to a river (actually the Grand Union Canal at Yeading), and characters sometimes travelled to Maidenhead.
The newly introduced Warrington family became key figures in the show's on-going storylines; Nikki Warrington (Rebecca Blake) endured problems in her marriage and her large blended family, which consisted of her doctor husband Andrew (Simon Cook), his children Luke (Royce Cronin) and Sara (Beth Cordingly), and Nikki's children Becky (Chandra Reugg) and Darren (Joe Fox, later Ike Hamilton) from her previous marriage to incarcerated Adrian Scott (Ariyon Bakare).
The places in their flat were taken by a succession of attractive young residents, including Polly Arnold (Juliet Cowan) and Dr Tanya Ayuba (Laila Rouass).
Karen Ellis embarked upon a controversial lesbian affair with her child's surrogate mother, Sadie's Australian niece Kelly Hurst (Nicky Talacko).
Mother Ginny (Joanna Foster) was recovering from a severe bout of depression, and husband Robert (Brian Cowan) worked to launch a catering business on Stanley Street.
Their three teenage children Jessica (Sammy Glenn), Cameron (Rupert Hill) and Lewis (Sam Stockman) were soon joined by Robert's much younger adoptive brother Jude Davenport.
Meanwhile, Yasmin and Benji's aunt Pearl moved away, and a guilt-racked Siobhan Callan endured prison and a lengthy court case after being framed for Josh's murder.
In September 2003, another drastic cast revamp occurred as new series producer Alison Davis arrived, presented with the task of finally getting viewing figures up to an acceptable standard.
The driver was Dave Matthews' recently arrived stepson Jake Walker (Seb Castang), who lost control of the stolen car during a police chase following a botched deal by Gabriel Drummond.
The biggest casualty of Davis's arrival was the show's only remaining original character, Roy Farmer, who was killed in a fire at his Internet café business.
In league with the sinister Mike Shaw (Tony O'Callaghan), Eileen had started the fire that killed Roy, in an attempt to frame Pete for arson.
Doug MacKenzie (Gareth Hale) became Cat Webb's third husband, while his womanising son Marc (Michael Wildman; later Graham Bryan) married Yasmin.
During one of many marital upsets in the Costello household, daughter Chloe retreated upstairs and rifled through older sister Melanie's possessions, only to find a stash of MDMA; she subsequently took several of the pills and wound up in hospital.
Several other characters, including Sadie, Dave and Lucy, were written out of the series as Alison Davis ended her reign, to be replaced by ex-Hollyoaks producer Sean O'Connor.
O'Connor quickly outlined his plans for the show, including a name change and many younger, more glamorous characters (which threatened to turn the soap into a Hollyoaks clone).
Perhaps, most significantly, Family Affairs has often been acclaimed for its constant inclusion of minority groups, having featured a higher density of gay and lesbian characters over its history than any other British soap.
Partly, as a result of the storyline, Kazia Pelka, who played Chloe's mother Chrissy, also won the award for Best Dramatic Performance, culminating in a double victory for the show.