Cæstor

Cæstor, also spelled Castor, is a figure from Roman mythology. He is most famously known as one half of the Gemini twins, the other being his brother Pollux. Together, they are often referred to as the Dioscuri, a name derived from the Greek "Dioskouroi," meaning "sons of Zeus."

In Roman tradition, Cæstor was the mortal son of Leda and Tyndareus, king of Sparta. His twin brother, Pollux, was the immortal son of Leda and Zeus. This divine parentage for Pollux, and mortal for Cæstor, is a significant aspect of their myth, leading to their shared but distinct fates.

The Dioscuri are renowned for their adventures and bravery. They are often depicted as skilled horsemen and warriors, participating in significant events such as the Calydonian Boar Hunt and the voyage of the Argo. Their devotion to each other is a central theme in their mythology.

According to the myth, when Cæstor was killed in battle, Pollux was so grief-stricken that he renounced his immortality to be reunited with his brother. Moved by their fraternal love, Zeus granted them the ability to spend half their time in the underworld and half in Olympus, or alternatively, to shine as the stars of the constellation Gemini. This allowed them to remain together, a symbol of eternal brotherhood and loyalty. Cæstor is often associated with horses and boxing.