AN INTRODUCTION TO
IOANNES REGIOMONTANUS’ ACROSTIC,
CARDINAL BASILEIOS ‘IOANNES’ BESSARION’S AGENDA,
AND PIERO DELLA FRANCESCA’S ENIGMA
by David A. King,
inspired by two remarkable discoveries by Berthold Holzschuh

There
is a connection between the astrolabe that Regiomontanus gave to
Cardinal Bessarion in 1462, and “The Flagellation of Christ” by Piero
della Francesca. For a brief summary see below. For an introduction of
50 pages click here. For a “silent lecture” (over 200 pdf images including explanatory text) click here. For a full account see David King, Astrolabes
and Angels, Epigrams and Enigmas – From Regiomontanus’ Acrostic for
Cardinal Bessarion to Piero della Francesca’s “Flagellation of Christ”, Stuttgart: Franz Steiner, 2007.
SUMMARY
Only recently have we achieved new insights into two monuments to the
intellectual genius of the Renaissance, an astrolabe and a painting.
Both are objects of exceptional beauty and each is based on
sophisticated mathematical notions. Each of these has caused scholars –
historians of science and historians of art, respectively – a great
deal of trouble. As it happens, the two are intimately related.
One is an astrolabe – a model of the three-dimensional heavens in two
dimensions – that was presented to the ageing Greek Cardinal Bessarion
in Rome in 1462 by his new protégé,
the young German astronomer Regiomontanus. This is engraved with the
image of an angel and an ingenious Latin epigram that is geometrically
arranged. Epigrams were very popular in Antiquity and in the
Renaissance, but this one is unique of its genre. Here eight hidden
vertical axes of an acrostic contain all sorts of hidden messages that
would have especially pleased the Cardinal once he had figured them
out: references to himself and his rank, to Regiomontanus, and to an
old Byzantine astrolabe that he had shown to the young German. The
angel is Bessarion, but not the Cardinal. There are several plays on
the Latin word cardo, meaning “hinge, axis or pole”. In
brief, two astrolabes come together in one, two poems, two languages,
two Bessarions, two men who used the name Ioannes, two places, Rome and
Constantinople, all come together in one.
When Bessarion saw the epigram, he must very quickly have noticed
something about the letters that Regiomontanus cannot possibly have
intended, namely, that – mainly by chance – groups of them reminded him
of various people who were involved in the Passion of Christ, the Fall
of Byzantium, or his own political, intellectual and personal agendas.
The other monument is a painting, “The Flagellation of Christ”, the
most enigmatic and controversial work of the leading
mathematician-artist of 15th-century Italy, Piero della Francesca. The
symbolic flagellation with five persons takes place in the background
on the left, and in the foreground on the right there are three
“modern” figures: a Greek ambassador, a young man with a rather angelic
face, and an Italian dignitary. These images are not contemporaneous
portraits, for otherwise they surely could have been definitively
identified. In the past 150 years over 40 attempts have been made to
identify these three men, with wildly different results. In fact, until
recently, nobody had ever convincingly explained who or what these
three persons represent. This is because the “programme” behind the
painting owes its inspiration to the angel and the letters of the
epigram on Regiomontanus’ astrolabe.
The geometry and symmetry of the painting reflect those of the epigram,
and the letters of the epigram – read from left to right but also from
right to left – suggest double or multiple identities for each and
every one of the nine images – eight persons and the classical god on
top of the column behind the Christ-figure – that are found in the
painting. It is not surprising that we can find the letters for these
names amongst the letters in the epigram; what is surprising is that
the names we can find for the first five spaces correspond to the five
persons and one classical god in Piero’s Flagellation scene, further
providing a selection of very likely candidates for the three men on
the right. The bearded man is Bessarion, but his facial features show
him more as he might have looked in Florence in 1439 before he became a
Cardinal. Nevertheless the image does represent the Cardinal because
the angelic figure in cardinal red beside him represents the young
Regiomontanus, whom the Cardinal had brought to Italy in late 1461.
However, the image representing the young German embodies five other
persons, three who had died recently and two who were long dead, all
close to Bessarion’s heart. Part of the complex iconography is the
decoration with thistles on the gown of the three individuals
represented in the one man on the right: this is now a play on the
Italian word cardo, meaning “thistle”, and one of their family names.
Both the astrolabe and the painting may be “smoking guns” but both are
silent about the way in which the epigram actually inspired the
painting. The clues to the connection between the two are mainly
mathematical. The readings of groups of letters in the epigram to
derive names for the persons in the painting are inevitably subjective
and the findings presented here are all hypothetical. However, they are
sufficiently convincing that this author believes that he is not the
first to have looked at the epigram in this way.
We have no record of an encounter between Bessarion and Regiomontanus
on the one side, and Piero and a potential sponsor on the other.
However, some occasions do present themselves on which the Cardinal and
his protégé
might have passed through Piero’s hometown of Sansepolcro, or nearby
Arezzo, where Piero was working on the spectacular frescoes known as
“The Legend of the True Cross”.
The painting once bore a title, long since removed, namely, the Biblical phrase Convenerunt in unum,
“they came together in one”. The basic meaning applies equally well to
the astrolabe. Somehow, Bessarion and Regiomontanus, maybe with the
help of some close friends, developed the idea for this remarkable
painting in which over twenty people and four classical gods come
together in three different scenes at three different times, all coming
together in one in spectacular perspective.