The Ancient Britons were a group of people who lived in Britain before the Roman invasion. They were composed of three main tribes: the Picts, the CELTS, and the Iceni. The Picts were a tribe of people who lived in what is now Scotland and northern England. The CELTS were a group of people who lived in what is now Wales, Ireland, and parts of England. The Iceni were a tribe of people who lived in what is now East Anglia.