Methodism, or the Methodist movement, is a group of historically related denominations of Protestant Christianity which derive their inspiration from the life and teachings of John Wesley. George Whitefield and John's brother Charles Wesley were also significant leaders in the movement. It originated as a revival within the 18th-century Church of England and became a separate Church after Wesley's death. Because of vigorous missionary activity, the movement spread throughout the British Empire, the United States, and beyond, today claiming approximately 80 million adherents worldwide.