George Robert Sims was born on 2 September 1847 in Kennington, London, the eldest of six children born to George Sims and Louisa Amelia Ann Stevenson Sims, who gave Sims early exposure to both progressive politics and the London theatre. Louisa Sims was a president of the Women's Provident League and daughter of the Chartist leader, John Dinmore Stevenson, who in retirement lived with the Sims family; Sims attributed his early development of political views to his grandfather's influence. Sims's father was a wine merchant and later a dealer in cabinets and plate-glass. Sims's parents mixed in artistic and politically progressive circles and Sims had a comfortable upbringing in Hamilton Terrace, Islington. Sims was firstly educated at a preparatory school in Eastbourne, followed by Hanwell College (a military school) and then the University of Bonn. He was married three times, outliving his first two wives. In 1876 he married Sarah Elizabeth Collis (b. 1850) and in 1888 he married Annie Maria Harris (b. 1859). In 1901 he married Elizabeth Florence Wykes of Birmingham (b. 1873). He did not have children from any of the marriages. However, through marriage to Florence, he gained a step-niece, Florence Wykes 'Minty' Lamb (b. ca. 1900), who lived with Sims at least intermittently, and Sims appears to have doted on her. Minty's mother, Gertrude Wykes (sister of Florence) appears to have been an actress and her daughter, 'Minty Lamb', was a child entertainer (dancer and actress).
Sims's interest in journalism apparently began at school, where he wrote for The College Gazette (a hard-bound manuscript volume for 1862 is present in the collection; see GRS/9/1). His first appearance in print was a poem called 'A Face in the Crowd', published in a periodical called The Welcome Guest, 21 May 1864 (also present in the collection; see GRS/10/2). He then went on to write pieces for Fun, Weekly Dispatchand The Referee, where he published a popular column of miscellany called 'Mustard and Cress' under the pseudonym 'Dagonet' from 1877 until his death in 1922. This column proved so popular that selections were republished as books, The Dagonet Ballads (1879) and Ballads of Babylon (1880), his best-known ballad, 'It is Christmas Day in the Workhouse', being from the 1879 collection. Through his journalism he was a vocal campaigner for the plight of the urban poor and he was appointed to take part in an 1882 study of social conditions in Southwark and as a witness for the 1884 Royal Commission on Working-Class Housing. Sims was involved with several social campaigns and movements including: campaigning for the promotion of 'improving' entertainments on Sundays with the National Sunday League; the Temperance Movement (for the working-classes); he also co-founded the Children's Breakfast and Dinner Fund (1880), providing free food for poor children, and was active with the Boys' Club Movement. Along with writing about the social conditions of the working-classes, Sims's journalism also included travelogues and articles about leisure and sport, and his hobbies - dog breeding and horse racing. Also reflected in his journalism was a keen and long-held interest in the Jack the Ripper murders and Sims developed his own theories on the subject.
As an author of dramatic works, Sims's output was prolific, diverse and sustained. His work was popular melodrama aimed at the masses, involving contemporary social concerns and gender, class and racial stereotypes. Sims formed a typology of genres for his works and frequently included them in their titles including: Comic Opera; Drama; Comedy; Farce; Burlesque; Musical Comedy; and Melodrama. He frequently collaborated with other writers on the works and co-authors included at different times: Robert Buchanan (1841-1901); Henry Pettitt (1848-1893); Clement Scott (1841-1904); Cecil Raleigh (1856-1914); Leonard Merrick (1864-1939); Sydney Grundy (1848-1914); and Arthur Shirley (1886-1967). He also collaborated with several composers on his musical dramas including Meyer Lutz (1829-1903), Ivan Caryll (1861-1921) and Frederic Clay (1838-1889). Many performances of his dramas included famous stage actors/performers of the time, such as Dan Leno (1860-1904) and Mrs Patrick Campbell (1865-1914). Several of Sims's stage works proved very popular and enjoyed notable longevity. The Lights O' London (1881) ran for 286 nights at the Princess's Theatre, London, before touring the English Provinces, the United States and Europe. Little Christopher Columbus (1893) ran for 421 performances at the Lyric Theatre and then Terry's Theatre, London. Sims is said to have been the first playwright to have four plays running simultaneously in the West End. Besides writing pieces for the stage, Sims was also a prolific published author writing books of poetry, crime fiction, journalism (social concern), dramatic fiction and several volumes of memoirs/autobiography.
Besides being a popular and well-known playwright, journalist, author and social campaigner, Sims could be said to have been a celebrity: during the early 1900s, many articles were published about his home-life and family life, the appearance and contents of his home and also hobbies and interests, including articles on his dogs, his interest in sport (in particular horse racing and boxing) and also articles mentioning his interest in gardening and the occult. His third marriage to Florence, in 1901, received much press coverage and there were many published cartoons which satirised the appearance of the man and his work. In 1906 he used his celebrity status to campaign for the pardon of Norwegian, Adolph Beck, who was twice imprisoned due to mistaken identity. Sims also used his celebrity status to invent, produce and endorse a hair-restoring remedy, known as Tatcho, registered in 1897.