Brook is an English name derived from the Old English word "broc," which means a small stream or brook. It is believed to have originated as a surname given to people who lived near a brook or a stream. The earliest recorded use of the name Brook dates back to the 13th century.

The name Brook has its roots in the Germanic languages, with similar words found in Old Norse, Old Saxon, and Old High German. In Old Norse, the word "brukka" meant a brook or a stream, while in Old Saxon, it was "broc," and in Old High German, it was "bruoh."

One of the earliest known references to the name Brook can be found in the Domesday Book, a manuscript record of the great survey of England completed in 1086 AD. The name is mentioned in various entries, indicating that it was in use as a surname during the Norman Conquest.

Throughout history, several notable individuals have borne the name Brook. One of the earliest was Sir David Brook (c. 1275-1326), an English knight and landowner who served under King Edward II. Another notable figure was Sir John Brook (c. 1430-1513), an English soldier and courtier who fought in the Wars of the Roses.

In the 16th century, the name gained prominence with the English philosopher and statesman Sir Robert Brook (1537-1598), who served as a Member of Parliament and was involved in the translation of the Bible into English.

During the 17th century, the name was associated with the English clergyman and author Thomas Brook (1608-1680), known for his religious writings and sermons. Another noteworthy individual from this period was the English naturalist and explorer John Brook (1631-1691), who explored and documented the natural history of New England.

In the 18th century, the name was carried by the English poet and playwright Henry Brook (1705-1763), known for his satirical works and collaborations with writers like Alexander Pope.

While the name Brook has been used predominantly as a masculine name throughout history, it has also been given to females, particularly in more recent times. However, the historical records and references mainly focus on its use as a male name.