Existentialism is a philosophical movement that began in the 19th century and gained popularity in the 20th century, particularly in Europe. It is rooted in the idea that human existence is characterized by alienation, anxiety, and a lack of purpose. Existentialists believe that by accepting and embracing these aspects of life, individuals can find meaning and fulfillment. Existentialist thinkers such as Jean-Paul Sartre, Martin Heidegger, and Albert Camus have had a profound influence on philosophy, literature, and culture. The existentialist movement was particularly influential in the aftermath of the First and Second World Wars, when many people felt a sense of alienation and despair in the face of widespread destruction and death.