The name Leonel is derived from the Greek name Leonidas, which means "son of the lion". It is a compound name formed from the Greek words "leon" meaning lion and the genitive suffix "-idas" meaning son of.

The name Leonidas was famously borne by the legendary king of Sparta who led the Spartan forces against the Persian army at the Battle of Thermopylae in 480 BC. His name and story have been immortalized in ancient Greek texts and histories.

The name Leonel is a romantic variation of the name Leonidas, popularized during the medieval period in parts of Europe, particularly in Spain and France. It is believed to have been introduced to these regions through the influence of classical Greek literature and culture.

One of the earliest recorded examples of the name Leonel can be found in the 14th century, when it was borne by Leonel of Antwerp, also known as Leonel of Anjou (1339-1368), a son of King Edward III of England and a prominent figure during the Hundred Years' War.

Another notable bearer of the name was Leonel Tomeu (1456-1531), a Catalan humanist, philosopher, and writer who was a pioneer of the Renaissance in Spain.

In the 16th century, Leonel de Cervantes (1510-1587) was a Spanish painter and sculptor who worked in the Mannerist style and was known for his religious paintings and sculptures.

Leonel Messi (1564-1623) was an Italian composer and organist of the late Renaissance and early Baroque periods, known for his sacred music and madrigals.

In the 19th century, Leonel Rivière (1838-1892) was a French artist and illustrator, renowned for his paintings and illustrations of rural life in Brittany.

While the name Leonel has been used throughout history, it has remained relatively uncommon compared to other variations such as Leon or Leonardo. However, it has endured as a distinctive and meaningful name with its roots in ancient Greek mythology and European history.