Charles Bradlaugh left his home in East London at the age of 16 due to religious differences with his family and was assisted by Elizabeth Sharples Carlile, widow of Richard Carlile the publisher of Tom Paine's Rights of Man and by G. J. Holyoake. To earn a living, he enlisted in a Guards regiment and was posted to Dublin, but after two years obtained discharge and found work in a law office, and began writing secular articles as "Iconoclast".
In 1858 he became president of the London Secular Society, in place of Holyoake. With Joseph Barker in 1860 he founded The National Reformer and in 1866 helped to establish the National Secular Society, opposed to Christian dogma.
In 1877 Charles Bradlaugh and Annie Besant published a new edition of The Fruits of Philosophy by Charles Knowlton, advocating birth control. They were charged with publishing material "likely to deprave or corrupt those whose minds are open to immoral influences" and were found guilty of publishing an "obscene libel" and sentenced to six months in prison. At the Court of Appeal the sentence was quashed.
In 1880, elected MP for Northampton, he asked for permission to affirm the oath of office, instead of 'swearing' on the bible, but was refused and expelled from Parliament. This turned into a struggle over the next three years, involving arrests, imprisonment, forcible ejection, campaigns, lodging a petition, being fined and the attempt by Gladstone to pass an Affirmation Bill, until at last, with a new Speaker, he had the right to speak and vote. Eventually in 1888 a new oath act was passed.
He supported Irish Home Rule and the redistribution of land, opposed the military involvement in South Africa, Sudan, Afghanistan and Egypt. His funeral in 1891 was attended by 3,000 mourners.