The Constantinopolitan Creed, commonly known as the Nicene Creed, is a statement of Christian faith that was formulated at the First Council of Constantinople in 381 AD, building upon the original Nicene Creed established at the First Council of Nicaea in 325 AD. It is a pivotal document in Christian theology, used by many denominations to articulate core beliefs about the nature of God, Christ, and the Holy Spirit, and it played a significant role in unifying Christian doctrine during a time of theological disputes.