[2]) They moved to Finchley in North London, but young Harold commuted daily to his East End grammar school, to avoid any disruption to his education.
He went to St Bartholomew's Hospital to start his medical training in 1940, treated air raid casualties, and met and married a non-Jewish nurse, named Judith Martin.
He never remarried, despite the hard work of matchmaking aunts and Dr Legg since devotes his life to keeping the residents of Albert Square healthy.
Dr Legg later moved to Islington, living there for several years, but continued to maintain his surgery in Albert Square, renting the flat upstairs to Ethel Skinner (Gretchen Franklin) and the barman Lofty Holloway (Tom Watt) among an array of other tenants.
[3] As Walford's GP, Harold is forever getting called upon to treat the troubled residents, even when he is not on duty, including helping Sue Osman (Sandy Ratcliff) come to terms with the death of her son, and humouring hypochondriac Dot Cotton (June Brown).
In 1988, Harold's sister, Hester Samuels (Barbara Shelley), comes to Walford to visit and tells him that her son, David (Christopher Reich), is interested in joining him in Britain.
Harold also disagrees with David's friendship with their secretary, Michelle Fowler (Susan Tully), particularly when the two get drunk at a Christmas party, leave together and share the same bed.
[3] David later becomes incensed by his uncle's lack of persistence concerning Donna Ludlow's (Matilda Ziegler) heroin addiction and blames him for her death later in the year.
In December 2008, he telephones Dot with news of Janine Butcher (Charlie Brooks), now known as Judith Bernstein, and her upcoming wedding to an elderly Jewish man.
As per Jewish customs, Dr Legg is buried the next day and Dot leads a memorial service for him with many, including Lofty and Mary, arriving to pay their respects to him.
Dr Legg was an attempt to represent the successive wave of Jewish immigrants that had settled in the East End of London between 1881 and 1914 in order to avoid the persecution that they were being subjected to in the rest of Europe.
[4] The second generation of East End born Jews (as Dr Legg was meant to represent) prospered in the area until the 1930s when Oswald Mosley's British Union of Fascists was formed, and used violence to instil fear in the Jewish population.
[5] As the Jewish community grew wealthier, many moved out of the East End to more affluent areas of London,[5] just as the character of Dr Legg had done on-screen when the show began; living in Islington, but commuting to his practice in Walford.
Dr Legg's original character outline as written by Smith and Holland appeared in an abridged form in their book, EastEnders: The Inside Story.
Holland and Smith had difficulties in casting the role of Dr Legg, as they had problems finding an actor of the right age, intelligence, and class, who could also play a Jewish professional man.
His personal life was largely kept hidden from viewers, although he would occasionally reminisce about his and Albert Square's history, mainly with other characters supposedly born in the area, such as Ethel Skinner (Gretchen Franklin), Lou Beale (Anna Wing) and later Benny Bloom (Arnold Yarrow).
Within the novelisation entitled Home Fires Burning, readers were made privy to the character's history as a trainee doctor during World War II, and his blossoming relationship with his would be wife, Judith.
Although his first name of Harold was first spoken by the visiting DI Marsh (Harry Miller) in the final scene of the show's second episode in 1985, he has always been referred to by the majority of the other characters and in the closing credits as "Dr Legg".
[10] On Dr Legg's return, Yorke commented, "It's a huge honour to have Leonard back in the show and to see him and June working together again for an exciting and emotional story.
"[10] In 2020, Sara Wallis and Ian Hyland from The Daily Mirror placed Dr Legg 72nd on their ranked list of the best EastEnders characters of all time and called his 2019 send-off "special and well-deserved".