Karl Barth was a Swiss theologian born in 1886, known for his influential work in Christian theology during the 20th century. He is best recognized for his major work, the Church Dogmatics, which redefined Protestant theology and emphasized the sovereignty of God. Barth's ideas challenged liberal theology and focused on the importance of divine revelation through Jesus Christ. Barth's theology is often associated with the concept of dialectical theology, which stresses the tension between God's transcendence and immanence. He believed that human understanding of God is limited and that true knowledge comes from God's self-revelation. Barth's work has had a lasting impact on modern Christian thought and continues to be studied today.