Jolyon

Medieval form of JULIAN. The author John Galsworthy used it for a character in his 'Forsyte Saga' novels (published between 1906 and 1922).

JULIAN   male   English, Polish, German
From the Roman name Iulianus, which was derived from JULIUS. This was the name of the last pagan Roman emperor, Julian the Apostate (4th century). It was also borne by several early saints, including the legendary Saint Julian the Hospitaller. This name has been used in England since the Middle Ages, at which time it was also a feminine name (from Juliana, eventually becoming Gillian).
JULIUS   male   Ancient Roman, English, German
From a Roman family name which was possibly derived from Greek ιουλος (ioulos) "downy-bearded". Alternatively, it could be related to the name of the Roman god JUPITER. This was a prominent patrician family of Rome, who claimed descent from the mythological Julus, son of Aeneas. Its most notable member was Gaius Julius Caesar, who gained renown as a military leader for his clever conquest of Gaul. After a civil war he became the dictator of the Roman Republic, but was eventually stabbed to death in the senate.

Although this name was borne by several early saints, including a pope, it was rare during the Middle Ages. It was revived in Italy and France during the Renaissance, and was subsequently imported to England.
JUPITER   male   Roman Mythology (Anglicized)
From Latin Iuppiter, which was ultimately derived from the Indo-European *Dyeu-pater, composed of the elements Dyeus (see ZEUS) and pater "father". Jupiter was the supreme god in Roman mythology. He presided over the heavens and light, and was responsible for the protection and laws of the Roman state. This is also the name of the fifth and largest planet in the solar system.
ZEUS   male   Greek Mythology
The name of a Greek god, related to the old Indo-European god *Dyeus whose name probably meant "shine" or "sky". In Greek mythology he was the highest of the gods. After he and his siblings defeated the Titans, Zeus ruled over the earth and humankind from atop Mount Olympus. He had control over the weather and his weapon was a thunderbolt.
EQUIVALENTS
ANCIENT ROMAN: Iulianus
BASQUE: Julen
BULGARIAN: Yulian
ENGLISH: Julian, Julyan
FRENCH: Julien
GERMAN: Julian
ITALIAN: Giuliano
POLISH: Julian
ROMANIAN: Iulian
RUSSIAN: Yulian
SPANISH: Julián
DIMINUTIVES AND SHORT FORMS
ENGLISH: Jools, Jules
FEMININE FORMS
ANCIENT ROMAN: Iuliana, Juliana
BULGARIAN: Yuliana
CROATIAN: Julijana
DUTCH: Juliana
ENGLISH: Gill, Gillian, Jill, Jillian, Jillie, Jilly, Juliana, Julianna, Julianne, Leanna, Liana
FRENCH: Juliane, Julienne
GERMAN: Juliana, Juliane, Liane
HUNGARIAN: Julianna
INDONESIAN: Yuliana
ITALIAN: Giuliana, Liana
MACEDONIAN: Julijana
POLISH: Julianna
PORTUGUESE: Juliana, Liana
ROMANIAN: Iuliana, Liana
RUSSIAN: Uliana, Yuliana, Yulianna
SERBIAN: Julijana
SLOVENE: Julijana
SPANISH: Juliana
OTHER FORMS
ANCIENT ROMAN: Iulia, Iulius, Julia, Julius
BIBLICAL: Julia
BULGARIAN: Yuliya
CATALAN: Júlia
CORSICAN: Ghjulia
CROATIAN: Julija
CZECH: Julie
DANISH: Julia, Julie
DUTCH: Julia, Julie, Lia, Lieke
ENGLISH: Jools, Jules, Julia, Julie, Juliet, Julius
FINNISH: Julia
FRENCH: Jules, Julie, Juliette
GERMAN: Julia, Julie, Julius
HISTORY: Julitta
HUNGARIAN: Gyula, Juli, Júlia, Juliska, Lili
IRISH: Iúile
ITALIAN: Giulia, Giulietta, Giulio
LATVIAN: Jūlija
LITHUANIAN: Julija
NORWEGIAN: Julia, Julie
POLISH: Julek, Julia, Julita, Juliusz
PORTUGUESE: Júlia, Julie, Julinha, Julio
ROMANIAN: Iulia, Iuliu
RUSSIAN: Julia, Juliya, Yuli, Yulia, Yuliy, Yuliya
SLOVAK: Júlia, Július
SLOVENE: Julij, Julija
SPANISH: Julia, Julie, Julio
SWEDISH: Julia
UKRAINIAN: Julia, Juliya, Yulia, Yuliya