Sean O'Casey was an Irish playwright born on March 30, 1880, in Dublin, Ireland. He is best known for his works that depict the struggles of the working class in Ireland during the early 20th century. His most famous plays include The Shadow of a Gunman, Juno and the Paycock, and The Plough and the Stars, which explore themes of poverty, conflict, and social injustice. O'Casey's writing style is characterized by its use of realistic dialogue and vivid characters. He was a significant figure in the Irish Theatre movement and often challenged the romanticized views of Irish life. O'Casey passed away on September 18, 1964, leaving a lasting impact on modern theatre.