A 5th century medallion showing what is perhaps the only
portrait we have of Galla Placidia (388-450 c.e.), the last (and
the only) Western Roman Empress. The inscription says "Domina
Nostra, Galla Placidia, Pia, Felix, Augusta," that is "Our Lady,
Galla Placidia, Pious, Blessed and Venerable." A contemporary of
such figures as Saint Augustine, Saint Patrick, Attila the Hun,
and – perhaps – King Arthur, Placidia had the rare chance of
being able to do something that past Roman Emperors never could
do; take the Empire to its next stage which was to be,
unavoidably, its demise. As I was preparing this essay on
Empress Galla Placidia, I found myself giving an impromptu talk
on the subject to my students in chemistry on the last lesson
before Christmas. Later on, I thought that I could write my
essay in the form of that talk. So, here it is. It is much
expanded in comparison to what I said to my students on that
occasion, but still it maintains the essence of it. I have added
headings and some figures. Introducti