We are going to delve down to the roots of the language and deduce its history - and in that one sentence we hear words from four different sources; delve from Dark Age Anglo-Saxon, root from Danish invaders, language from medieval French, and deduce from Renaissance Latin; four of the main - but not all - contributors to the richness of modern English.

We see how England was ruled for three centuries after the Conquest by a French-speaking king and court which used Latin for their official business. English was the language of the peasants; a third-class tongue in its own country.

This is the story of how English became the battleground in the fight for men's souls. The medieval church establishment kept the Bible in Latin, while those possessing an English translation risked death. We see the impact of printing on the English language, and how that fixed many of the anomalies of spelling and grammar that still make English so difficult for students to learn.

Visiting the England of Queen Elizabeth the First shows how naval enterprise and foreign trade brought scores of new words into the language. Scholars were bringing new Latin terms into the language, and there was a movement to stop this and keep English 'pure'. Shakespeare combined the languages of the common people and the aristocracy to take English to new heights and to invent so many memorable words and phrases.

Following the English language on its journey overseas and tracing the story of how the language of the British Isles became a language for the world - the most widely spoken and understood vernacular in history. In America the language of a small group of seventeenth-century English immigrants only survived through the most unlikely coincidence – but America was to develop a vigorous new vocabulary, and to spread it around the globe.

In eighteenth century Britain, the first English dictionary was produced. A cohort of grammarians imposed new rules on the language. English continued to change and develop and the way people talked and the words they used became a badge of class and breeding and social death could result from dropping an ‘h’ or using an inappropriate word.

Travelling to parts of the former British Empire, we see how English met other cultures and other languages, and was enriched by them. We travel to India to see how English began as the language of a few hundred pioneer merchants and became the force that unified an Empire of a thousand tongues. In the Caribbean Bragg discovers how a whole flock of new English dialects grew out of a mix of European and African influences, and in Australia he traces how the slang of transported convicts grew in confidence and finally escaped from the shadow of Standard English.

The concluding episode looks at how in the 20th century the rise of America as an industrial power has made it the driving force behind the global spread of English. The English language is now used by more people than ever before in history. As cultural influences affect the way people use English and new words come into everyday use, how does the Oxford English dictionary – the greatest repository of the language – keep up with developments.