From the 5th century CE, the Anglo-Saxons settled Britain as the Roman economy and administration collapsed.
By the 7th century, the Germanic language of the Anglo-Saxons became dominant in Britain, replacing the languages of Roman Britain (43–409 CE): Common Brittonic, a Celtic language, and Latin, brought to Britain by the Roman occupation.
The earliest forms of English, a group of West Germanic (Ingvaeonic) dialects brought to Great Britain by Anglo-Saxon settlers in the 5th century, are collectively called Old English.
Middle English began in the late 11th century with the Norman conquest of England; this was a period in which the language was influenced by French.
It is estimated that there are over 2 billion speakers of English.
English is the most commonly spoken language in the United Kingdom, the United States, Canada, Australia, Ireland and New Zealand, and it is widely spoken in some areas of the Caribbean, Africa and South Asia.
These left a profound mark of their own on the language, so that English shows some similarities in vocabulary and grammar with many languages outside its linguistic clades—but it is not mutually intelligible with any of those languages either.
Some scholars have argued that English can be considered a mixed language or a creole—a theory called the Middle English creole hypothesis.
The Frisian languages, which together with the Anglic languages form the Anglo-Frisian languages, are the closest living relatives of English.
Low German/Low Saxon is also closely related, and sometimes English, the Frisian languages, and Low German are grouped together as the Ingvaeonic (North Sea Germanic) languages, though this grouping remains debated.