Olympias the Elder was the daughter of a wealthy Roman aristocrat who was one of the most important Roman Senators of Constantinople. The date of her birth is unknown, but she and her brother were raised by maid servants while her father was serving in the senate in Constantinople. Her father arranged for the engagement of Olympias to Constans, the son and heir to the throne of Constantine the Great. When Constans I became Emperor in 337 CE, he took Olympias under his protection allowing her to remain a virgin.
In 350 CE Constans I was assassinated on the orders of the usurper Magnentius. Vetranio. The general who defeated Magnentius was made Emperor in 356 CE, but abdicated nine months later. When Constantius II succeeded him as emperor, he gave Olympias as a bride to Arsaces II to create an alliance with Armenia. Olympias married King Arsaces II, but bore him no children before he died of natural causes in 361 CE. His cousin, Julian the Apostate, was named successor to the throne and King Arsaces II took a second wife who fiendishly arranged for the Holy Sacrament given to Olympias to be poisoned causing her early demise.