Ethel Mannin, he eldest of the three children of Robert Mannin, a postal worker and Edith Gray, a farmer's daughter, was born in Clapham on 11th October 1900. Her father was a socialist and encouraged her to have a career. In her biography she recalled: "My father does not care how I achieve happiness so long as I achieve it."
Her parents sent her to a local private school: In Confessions and Impressions (1930) she recalled: "The school called itself a preparatory school, hut for what it could possibly prepare anyone it would be impossible to say.... I was so agonisingly shy and timid that I was fair game for the older children's teasing. A group of the older girls would amuse themselves by tormenting me until I would say a funny little obscene word...here was also a girl of about twelve whom I thought both grown-up and beautiful, immeasurably beyond me, but she had nothing but contempt for me. She wore petticoats with wide lace to them, and knickers with coloured ribbons run through. She was fond of doing high kicks-presumably to show off this seductive lingerie. I knew a curious quickening of the senses at the sight of her; she was a dashing and lovely being infinitely removed from me. But I have forgotten her name. I suppose that it is because I unconsciously shrink from the memory of her. She was one of my sadistic persecutors."
As a young girl she began writing stories and the first of these appeared in the Lady's Companion in 1910. In 1915 she won a scholarship to attend a commercial school in London. According to her autobiography, Mannin fell in love with one of her teachers: "I loved her, dear heavens, how I loved her! Once when she kissed me at the end of one of our precious lovely Saturday afternoons I walked home in a trance of ecstasy. I loved her literally so much that it hurt, and she was for me the meaning of all things that are." The teacher was also a a member of the Independent Labour Party and the Fabian Society: "Through this Miss X I learned about George Bernard Shaw, the Fabians, Jingoism, and the Independent Labour Party."
After leaving school she found employment as a typist for the advertising agency, Charles F. Higham Ltd. She later recalled "I was given twenty-three shillings a week and was tremendously excited and happy." The following year Charles Frederick Higham promoted her to the post of copywriter. "At sixteen I was writing advertisements, running two house-organs - business magazines - and when I was seventeen was publishing my own stories, articles, verses, in a monthly magazine which Higham bought and left to me to produce." Her employer was to have a great influence on her career: "I have never met anyone to equal him; for sheer individuality he stands head and shoulders above all the others. He has a dynamic quality which I have never found in the same degree of intensity in anyone else.... We are alike in that we both know what we want of life and set out to get it by the most direct route and with unfaltering determination."
Mannin began a relationship with an artist who worked for Higham. "Every evening J.S. and I would have tea together and talk... He did most of the talking. I could not talk. I listened and my young mind sucked up knowledge like a sponge absorbing water." He introduced her to the work of Thomas Paine and Robert Green Ingersoll. She later recalled: "I was deeply religious until I was sixteen, and then the artist... who was my real education, put into my hands the essays of Robert Green Ingersoll and Thomas Paine's Age of Reason, together with a Rational Press Association Annual, and I became an agnostic." He also lent her books and articles by John Stuart Mill, William Morris, Upton Sinclair, Eugene V. Debs, Graham Wallas, Robert Cunningham Graham and Peter Kropotkin. On Sunday afternoons they went to Finsbury Park and heard Tom Mann speak.
In her autobiography, Confessions and Impressions (1930), she wrote: "I loved him in the perfervid way in which I had loved my Miss X., but at fifteen I was completely sexually unawakened, and even at sixteen, towards the end of our year's association, any manifestation of love-making from him completely bewildered me. I was sixteen and he was twenty-six. I became sufficiently awakened towards the end of the friendship to want to kiss and to be kissed by him, but any caressive intimacy from him merely troubled me. It seemed queer, and I resented it a little and wished he wouldn't." He was a conscientious objector during the First World War and in 1917 he returned to New Zealand in order to avoid joining the British Army.
In 1918 she became romantically involved with John Alexander Porteus (1885–1956), who was the general manager at Highams. She later wrote that during this period that "this friendship lit by passion" was the "happiest I have ver known". On 28th November, 1919, Mannin married Porteus: "I was a very young nineteen, in spite of the experimental adventurings - too young, and too much in love, to be depressed by the dreary registry office, the cold foggy day, and the fact that we had no money and no home." Soon after her marriage she gave birth to her only child, Jean.
With a young baby to look after, Mannin now worked from home. She still wrote advertisements and edited journals for Charles Frederick Higham: "I had a retainer fee from Higham... and increased my journalistic freelance output, and wrote extensively in the provincial press... My output was tremendous; the payment was small as it always is for a beginner. Eventually she turned to novel writing and published Martha in 1923. According to one critic, the novel "elaborately plots the life of the lovechild of an unmarried woman and the price the child has to pay for the sins of the parents." This was followed by the Hunger for the Sea (1924), Sounding Brass (1925) and Pilgrims (1927). The author of The Feminist Companion to Literature in English has argued that "these are socially and politically conscious works, alert to women's oppression".
In 1929 Mannin and Porteus separated and she bought a small house in Wimbledon. Her first volume of autobiography, Confessions and Impressions appeared in 1930. According to her biographer, Beverly E. Schneller: "In 1931 she published her first book of short stories, Green Figs, and her literary success made her popular with the press, who were eager for her progressive views on sexuality, motherhood and professionalism, and marriage."
Mannin was a supporter of progressive education and sent her daughter to Summerhill School. In 1931 she published Common Sense and the Child, a book about the educational theories of A. S. Neill. She argued that "all outside compulsion is wrong... inner compulsion is the only value". Mannin also suggested that "there is no such thing as the naughty child... there are only happy children and unhappy children." She also produced a novel, Linda Shawn (1932), on the subject of progressive education. Love's Winnowing (1932) was her first openly politically novel. In 1934 she began an affair with W. B. Yeats.
Mannin was political active and had declared herself to be a socialist in her early twenties. In 1935 she joined the Independent Labour Party and contributed articles to its journal, The New Leader. In 1936 she travelled to the Soviet Union but in her book, South to Samarkland, she expressed her disillusionment with communism although she always remained firmly on the left. Mannin married Reginald Reynolds, a fellow member of the ILP on 23rd December 1938. She became friendly with Emma Goldman and her next novel, Red Rose, was based on the life of her friend.
Mannin produced seven volumes of autobiography and fourteen travel books, recording her visits to Germany, India, Morocco, Burma, Egypt, Jordan, Italy, and elsewhere. In 1958 she published her first children's books. Mannin also published several books on philosophy including Loneliness: a Study of the Human Condition (1966) and Practitioners of Love: some Aspects of the Human Phenomenon (1969).
Virginia Nicholson, the author of Among the Bohemians (2002) argues: "Ethel Mannin didn't resent the passing of youth, but she felt displaced in the post-War world of the 1950s... In old age her pleasures were correspondingly elderly - good wine, good books, and her roses. Her robust impatience with humbug remained vigorous however. She continued to travel, espoused Buddhism, and signed up to a variety of liberal causes. Passion, she felt, was for the young, but 'the unending struggle against injustice and barbarism in the world' was perennial."
In 1977 Mannin published her final memoir, Sunset over Dartmoor. In July 1984 Mannin was injured in a fall at home in Shaldon, and died of pneumonia and heart failure at Teignmouth Hospital, on 5th December 1984. During her lifetime she had published over a hundred books.