English begins as the language of a few Germanic tribes who cross the North Sea and invade the British Isles, and Melvyn Bragg opens his series by tracing how their dialects took root and nearly disappeared before becoming the world's most spoken tongue. He follows the Anglo-Saxon settlement of Britain, the clash with the native Celtic languages it displaced, and the long stretch when English survived as a spoken vernacular with no prestige and no fixed spelling. The turning point Bragg builds the episode around is King Alfred, who defends Wessex against Viking invasion and then makes the deliberate choice to promote English, having key texts translated and copied so the language gains the status and permanence that Latin held elsewhere in Europe. Bragg narrates on location, walking the landscapes where these events happened rather than staying in a studio, and the episode ends with English established as a language of law and learning rather than just everyday speech.