The name Briana has its origins in the Celtic languages of ancient Britain and Ireland. It is derived from the old Celtic root words "bri" or "brig," meaning "hill" or "high." The earliest known use of the name dates back to the 7th century.

In ancient Celtic mythology, Bri or Brigh was the name of a goddess associated with poetry, inspiration, and wisdom. She was often depicted as a young woman with flowing hair and a radiant aura, symbolizing the power of creative expression and enlightenment.

The name Briana gained popularity during the Middle Ages, particularly among the noble families of Britain and Ireland. One of the earliest recorded instances of the name was Briana of Gwent, a 10th-century Welsh princess renowned for her beauty and intelligence.

In the 12th century, the name Briana was mentioned in the works of the renowned Welsh writer and cleric, Geoffrey of Monmouth. His famous book, "Historia Regum Britanniae" (History of the Kings of Britain), included references to a character named Briana, who was described as a brave and noble warrior.

During the Renaissance period, the name Briana became associated with artistic and literary circles. One notable figure was Briana di Firenze (1435-1492), an Italian poet and philosopher who was celebrated for her eloquent verses and intellectual discourse.

In the 19th century, the name Briana gained popularity in Ireland, where it was often used as a variant of the traditional Irish name Bríghid or Bridget. A famous bearer of the name was Briana Ní Mhurchú (1830-1905), an Irish language scholar and activist who played a significant role in preserving and promoting the Irish language and culture.

Other notable figures who bore the name Briana throughout history include:

1. Briana of Braganza (1633-1688), a Portuguese princess and patron of the arts.
2. Briana Wyndham (1701-1785), an English playwright and poet known for her satirical works.
3. Briana Fitzpatrick (1845-1920), an Irish nationalist and advocate for women's rights.
4. Briana Montague (1879-1964), a British anthropologist and explorer who conducted groundbreaking research in Africa and Asia.
5. Briana Castillo (1920-2005), a Mexican painter and sculptor renowned for her vibrant and expressive artworks.