Julia Maesa (about 170- about 226) was daughter of Julius Bassianus, priest of the sun god Heliogabalus, the patron god of Emesa in the Roman province of Syria. As her younger sister Julia Domna, she was among the most important women ever to exercise power behind the throne in the Roman empire.

Julia Maesa was married to Julius Avitus and had two daughters, Julia Mamaea and Julia Soaemias, each one mother of an emperor. Following the accession to the throne of her brother in law Septimius Severus, Julia Maesa moved to Rome to live with her sister. After the murder of Caracalla, her nephew, and the suicide of Julia Domna, she was compelled to return to Syria. But the new emperor Macrinus did not proscribe her and allowed her to keep her money. In Syria, Maesa engaged in a plot to overthrow the usurper and place one of her grandsons, Heliogabalus son of Julia Soaemias, in his place. In order to legitimise this pretension, mother and daughter rumoured that the 13-year-old boy was Caracalla's illegitimate son. The Julias were successful, mainly due to the fact that Macrinus was of an obscure origin without the proper politic connections, and Heliogabalus became emperor.

For her loyalty and support, Heliogabalus granted Julia Maesa with the title Augusta avia Augusti (Augusta, grandmother of Augustus). The support would not be with him for a long time, because when the teenager proved to be a disaster as emperor (even taking the liberty of marrying a Vestal virgin), Julia Maesa decided to promote Alexander Severus, another of her grandsons. Heliogabalus was forced to adopt Alexander as son and was murdered shortly afterwards.

Julia Maesa died in an uncertain date around 226 AD and, like her sister Domna before her, was deified.

See also: Women in RomeSeveran dynasty family tree