The name Breann is a modern variation of the Irish name Bríghid, which means "exalted one" or "the high one." It has its origins in Celtic mythology, where Bríghid was the name of an Irish goddess associated with fertility, poetry, healing, and smithcraft. The name was later adopted by early Irish Christians and became popular as a given name for girls.

The earliest recorded use of the name Bríghid can be traced back to the 5th century AD, when it was borne by St. Brigid of Kildare, a celebrated abbess and one of Ireland's patron saints. St. Brigid founded several monasteries and is revered for her piety, miracles, and charitable works. Her feast day, celebrated on February 1st, is still widely observed in Ireland and parts of Europe.

Over the centuries, the name evolved into various spellings and forms, including Brigid, Bridget, Bríd, Bride, and Bree. The spelling Breann emerged as a modern variant, likely influenced by the Gaelic spelling "Breanainn" and the English pronunciation of the name.

Notable historical figures with the name Breann or its variations include:

1. Brigid of Kildare (c. 451 - c. 525), the Irish abbess and patron saint.
2. Brigid of Sweden (c. 1303 - 1373), a Swedish princess and religious leader who founded the Brigittine Order.
3. Bridget Boland (1913 - 1988), an Irish politician and activist who served as the first female Lord Mayor of Dublin.
4. Bridget Riley (born 1931), a renowned British painter and one of the leading figures in the Op Art movement.
5. Brigid Berlin (1939 - 2022), an American actress, artist, and muse of Andy Warhol's Factory.

While the name Breann is not as widely used as its more traditional forms, it has gained popularity in recent decades, especially in the United States and parts of Europe. The name carries a rich cultural heritage and connections to Irish mythology, Christianity, and influential historical figures.