Remana culture (Ree-mahn-ah)

Literally taken from the question "what if Remus had beat Romulus" but pronounced like it's actually still Italian, this is an alternative version of Ancient Rome. Back after the seige of the Sea Peoples, the nymphs of the seas around what we might call the Mediterranean raised the sea level and so the main god feared and worshipped was Neptune, aka Poseidon, instead of Zeus/Jupiter. The planets do not get named their real-life names because of this, and neither do the months of the year, although there are more factors than that for why they are named differently. Additionally, when the ancient Remana people first encountered the Book of Sybil, they decided to follow it a little differently because they figured that the floods were a sign. Little did they know, the forest nymphs were also pushing for a change in the course of history at the time because actually following the book of Sybil leads to their prosperity, too.

Culture

Common Customs, traditions and rituals

"Raised to the Red" - instead of being raised to the purple, emperors wear red, which frankly is what ancient "purple" dye looked like to the naked eye sometimes.

Common Myths and Legends

Sylvia, the bio mom of Romulus and Remus, is a runaway from the battle of Troy in place of Aneas. 
Instead of being the adopted sons of wolves, Romulus and Remus are the adopted sons of a selkie. The sea folk bow in allegiance to them because of her and Remus leads them to victory against the forest folk, who then marry him in recognition of his superior military might.
Every river deity was already considered a child of Poseidon/Neptune, so there is no need for the disgusting "your goddess is now one of Zeus's mistresses punished by Hera."

Historical figures

Kings from 1665 to 2433 approximately - all married tree nymphs.
Somewhere around 2430 - Caesar Augustus rules, Yeshua starts a religion. Augustus's children are strictly forbidden from marrying each other. Instead of adopting the husband of your daughter whose marriage you picked out beforehand, their eligibility for the throne is only valid after the wedding takes place and you take a version of your wife's name in order to seal the deal.
Around 2490 - Caligula actually does declare war against the sea. And the sea fights back. The sea nymphs are responsible for urging plebians to distrust forest nymphs, the allies of the Remana emperors.
Nero - starts the persecution of both Jews and Yeshuans. His action of raising a group of retired marines and sailors instead of a land-based legion actually makes him a favorite of the sea folk, so they stop their attacks for a time.
Around 2500 - Year of the Four Emperors. Soothsayers giving rival predictions lead to four different fellows being raised to the red and fight each other to stay there. 

Effects on the present include, mainly, the reactionary cultural reforms created in the wake of the witches taking over Rema. In place of a unifying language (Latin), regional languages got a jump start and much more support in creation. Instead of a unifying pagan religion for Yeshuan bishops to fight against, it was allegiance to river deities who were gradually transformed into saints or visiting incarnations of Yeshua and his first disciples.