Arthur Koestler (1905-1983) was a Hungarian-British author and journalist. He is best known for his novel Darkness at Noon, which was a powerful indictment of the Stalinist purges of the 1930s. Koestler was also a prolific essayist and political activist, writing extensively on topics such as science, philosophy, and politics. He was a strong advocate for human rights and was a vocal critic of totalitarianism. Koestler was awarded the Sonning Prize in 1976 for his contributions to European culture. He is remembered as one of the most influential writers of the 20th century.