English became the dominant language in Britain for several reasons. The Roman Empire left a lasting legacy on British culture, including the use of Latin in government and law. After the Roman Empire collapsed in Britain, Anglo-Saxon settlers began to arrive in large numbers.
During the Middle Ages, English became the language of commerce and learning. In the 17th century, England began to experience a gradual decline in its cultural and linguistic dominance over other languages. This led to a rise in the use of French, Spanish, and other languages in Britain. English regained its dominant position during the Industrial Revolution.