Dr. Posanner grew up capital-R Rich. As the daughter of a wealthy financial minister of Austria, she moved often and was educated by some of the best private tutors money in Austria could buy.
As a naturally inquisitive albeit a little spoiled young lady, it was decided (for her) that she should become a teacher herself. She graduated in 1887 but was barred from studying further to become a full teacher, since women were not allowed to attend Universities in Austria until over a decade later.
Disillusioned, she moved to Geneva and later Zurich, first as a socialite, then attending medical school, which was open to women. However, to graduate she had to show a Swiss High School diploma (Matura), her private school diploma was not recognized. So, in 1890, she went back to High School (at 30 years old), completed her diploma there, and returned to Zurich, where she graduated as an MD in 1894.
Switzerland, a notoriously conservative and not very egalitarian country (the last Canton to give women the right to vote was Appenzell in 1990) was nevertheless open to female physicians, and she could have taken a position as a general practitioner or sought further training.
Instead, she returned to Vienna to take the only position open to a female physician, as a military doctor in Bosnia-Herzegovina (then under Austro-Hungarian rule), tending to Muslim women who refused to be seen by male physicians.
While doing so she spent most of her remaining fortune peppering everyone in power, government ministries, even Emperor Franz Joseph I, with letters demanding to be allowed to practice in Austria.
Two years later, in 1896, the Emperor caved and decreed, at least partially, as OB/GYN, that females must be allowed to practice. He also decreed, as the first in the world, that Austria would accept foreign diplomas in medicine. Possanner immediately applied and was accepted but was forced, as were some male colleagues coming back from Switzerland and Germany, to re-sit all exams.
She passed and was awarded an Austrian diploma on April 2 1896, at 36 years old. She opened her own clinic two months later.
Her PhD advisor wrote in the Viennese Weekend Newspaper:
Since women are in neither determination nor intelligence inferior to men, it is unfathomable why they would be denied higher professional callings. If empresses and queens can reach eternal glory through active and wise government, why would other women be considered incapable of assuming a role in higher professions?
The article also writes:
We can only repeat ourselves once more: year after year we mourn the victims that only passed because their sense of shame prevented them from seeking help with a male physician. They died because they could not find a female physician. There are no female physicians, in fact. We hope that Dr. v. Possaner (thus spelled!) will soon see sufficient female competition in this country.
This article, in one of the most-read and best regarded newspapers, significantly helped shift the attitude of fellow physicians, the public, and royal and common governing bodies towards accepting females into medical school and graduation.
In 1902 she entered as a Resident as the first woman into the Viennese Kronprinzessin Stephanie Hospital, but faced another hurdle two years later.
In the early 20th century, attending physicians had to be elected into this position by the local chamber of physicians. As a woman, Dr. Gabriele Barbara Maria Possanner von Ehrenthal was not eligible to vote or elected. Again, a major letter writing campaign ensued and, a year later, she was given full membership rights (along with any other female physician to come later) and was both allowed to vote and be elected, which she was a year later, culminating in her election to Medizinalrat, the second highest office in the chamber of physicians, in 1928.
Dr. Gabriele Barbara Maria Possanner, having dropped her royal name in favor of a common name, passed away on March 14 1940 in her sleep.