The name Brittanie originates from the ancient Britons, a Celtic people who inhabited what is now known as Great Britain during the Iron Age and Roman era. The name is derived from the word "Brython," which means "Briton" or "British" in the Brythonic Celtic languages.

In its earliest form, the name was likely spelled as "Bryten" or "Briten," reflecting the pronunciation used by the ancient Britons. As the name spread and evolved, it took on various spellings, including "Briton," "Britoun," and eventually "Brittanie."

One of the earliest recorded instances of the name Brittanie can be found in the Anglo-Saxon Chronicle, a collection of annals describing the history of the Anglo-Saxons in Britain. The chronicle mentions a figure named "Brittric" who lived in the 6th century and is believed to be a Briton chieftain or ruler.

Throughout history, several notable individuals have borne the name Brittanie. One of the most famous was Saint Brittanie (c. 480 - c. 570), a Welsh princess and Christian missionary who is credited with founding several churches and monasteries in Wales and Brittany, France. Her feast day is celebrated on April 28th.

Another prominent figure was Brittanie of Dol (c. 500 - c. 570), a Breton monk and abbot who founded the Abbey of Dol in Brittany, France. He played a significant role in the spread of Christianity in the region and is regarded as a patron saint of Brittany.

In the 11th century, Brittanie of Thouars (c. 1024 - 1109) was a powerful noblewoman and viscountess of Thouars in western France. She is known for her involvement in the political affairs of the time and her support for the Norman conquest of England.

During the 12th century, Brittanie of Vermandois (c. 1095 - 1183) was a French noblewoman and the countess of Vermandois. She played a crucial role in the Second Crusade and was known for her courage and leadership on the battlefield.

In more recent times, Brittanie Farrande (1584 - 1639) was an English explorer and navigator who is credited with being one of the first Europeans to map the coastline of New England and Nova Scotia in the early 17th century.