Martin Luther King, Jr. (born Michael King, Jr.; January 15, 1929 – April 4, 1968) was an American pastor, activist, humanitarian, and leader in the Civil Rights Movement. He was best known for improving civil rights by using nonviolent civil disobedience, based on his Christian beliefs. Because he was both a Ph.D. and a pastor, King is sometimes called the Reverend Doctor Martin Luther King Jr. (abbreviation: the Rev. Dr. King), or just Dr King. He is also known by his initials MLK.