Plancia’s ancestors, the Plancii, were among those Roman families that left Italy towards the end of the Republic. They made their fortune out in what is now Turkey, quite possibly in Perge, where Plancia Magna would eventually make her mark. She was the daughter of M. Plancius Varus and had a brother, C. Plancius Varus. At some point, probably when she was fairly young, she married C. Iulius Cornutus Tertullus, a man even more wealthy and powerful than her father, at least on a local level. The couple had a son, C. Iulius Plancius Varus Cornutus.
At some point in her life, probably in her younger years, Plancia began donating significant amounts of money for public works. Her most ostentatious project was the renovation of the city gate and inner courtyard in the early 2nd century. Among the statues are a pair depicting her father and brother, identified by their relationship to her** instead of the usual practice of identifying offspring by their father. Since she’s identified as the only donor, she probably paid for all of this from her own money, inherited from her father, and not from her husband’s coffers.
The gate and courtyard wasn’t her only donation, but it was probably her biggest. The city of Perge didn’t forget who had paid for all of it either. They named her “daughter of the city” and made her director of the gymnasium. She held three priesthoods, of Artemis (patron of the city”, of the Mother of the Gods,*** and of the imperial cult, and was named demiourgos.****
Plancia Magna was not the only wealthy woman to make extravagant public donations. She had the example of Empresses like Plotina and Vibia Sabina to look to, while women elsewhere in Anatolia made similar, though smaller donations to their own cities.
**This never happens. Ever. So this is a pretty big deal.
***She seems to have been the only one to ever hold this priesthood in Perge.
****A yearly magistrate whose name is used for dating events.
Boatwright, Mary Taliaferro. "Plancia Magna of Perge: Women's Status and Roles in Roman Asia Minor." In Women's History Ancient History, edited by Sarah B. Pomeroy, 249-272. Chapel Hill: University of North Carolina Press, 1991.
Salisbury, Joyce E. "Plancia Magna." In Encyclopedia of Women in the Ancient World, 279-281. ABC-CLIO, Inc., 2001.
Plancia Magna, Aurelia Paulina, and Regilla: Civic Donors - vroma.org