Thomas & Friends (originally known as Thomas the Tank Engine & Friends or simply Thomas the Tank Engine until series 7; later called Thomas & Friends: Big World! Big Adventures!) is a long-running British television series created by Britt Allcroft. Based on The Railway Series by the Reverend W. Awdry and later his son Christopher, it follows the adventures of Thomas, an anthropomorphised tank engine, on the fictional Island of Sodor with fellow engines Gordon, James, and Percy, and several other anthropomorphised vehicles. Thomas usually gets into trouble by doing jobs best left to bigger and more sensible engines, but never gives up on being a "Really Useful Engine".