Ellen Key was a daughter of Emil Key, a Swedish politician and landowner and his wife Sophie Posse, from an aristocratic family. She was born at their estate of Sundsholm in Småland and educated at home. When her father was elected to the Swedish Riksdag, the family moved to Stockholm. Ellen began writing book reviews, articles, and biographical sketches. In 1880, she became a teacher at a private girls' school and then at the Workers' Institute. She also contributed regularly to three Swedish journals. Her writings covered a wide range of topics: education, literature, art, religion, politics, women’s rights, love and marriage. In 1900, her book Barnets århundrade (The Century of the Child) made her world famous. In 1903, she gave up teaching to become a full-time freelance writer and started going abroad on lecture tours. Her liberal and radical opinions influenced many younger authors, including Selma Lagerlöf and Rainer Maria Rilke. In the late 1880s, she wrote biographies of several prominent Swedish intellectual women, including Victoria Benedictsson, Anne Charlotte Leffler, and Sonia Kovalevsky.