The name Adelia has its origins in the Latin language, stemming from the roots "adel" meaning "noble" and "ius" meaning "son". It emerged during the Middle Ages, particularly in regions with Latin cultural influences.

The name Adelia was initially used as a feminine form of the masculine name Adelius, which itself derived from the Germanic name Adalheidis or Adelheid. This Germanic name combined the elements "adal" meaning "noble" and "haid" meaning "kind" or "sort".

One of the earliest recorded instances of the name Adelia can be found in the 9th century, when an Italian noblewoman named Adelia di Bergamo lived during the Carolingian era. She was known for her philanthropy and support of religious institutions in the region.

In the 12th century, a French noblewoman named Adelia of Blois played a significant role in the crusades, accompanying her husband, Stephen of Blois, on the Second Crusade. She was renowned for her bravery and leadership during the arduous journey.

During the Renaissance period, Adelia Valvasone, an Italian poet and writer born in 1556, gained recognition for her works in both Italian and Latin. Her poetry explored themes of love, nature, and the human condition.

In the 18th century, Adelia Opie, an English author and poet born in 1769, made her mark with her literary works, including novels and poems that often addressed social issues and women's rights. She was also a prominent figure in the abolitionist movement.

Another notable figure with the name Adelia was Adelia Maria Sharpe, an American humanitarian and philanthropist born in 1824. She dedicated her life to improving education and healthcare for underprivileged communities, establishing schools and hospitals throughout the United States.

Throughout history, the name Adelia has been associated with nobility, grace, and a strong sense of purpose. While its usage may have ebbed and flowed over the centuries, it has endured as a name that carries a rich cultural heritage and a connection to influential figures from various eras.