A.J. Cronin was a Scottish author and physician, born on July 19, 1896, in Cardross, Scotland. He is best known for his novels that often explore themes of morality, social justice, and the human condition. Some of his most famous works include The Citadel, which critiques the medical profession, and The Keys of the Kingdom, which tells the story of a missionary in China. In addition to his literary contributions, Cronin's background as a doctor influenced his writing style and subject matter. His experiences in medicine provided him with insights into the struggles and triumphs of everyday people. Cronin's works have been adapted into films and continue to resonate with readers today.