The Boethius Diptych

The Roman consul Boethius commissioned ivory diptychs as gifts for his supporters on the occasion of his inauguration in 487 CE. One of them has survived. It shows the enthroned and standing consul in relief in his official clothes. It is preserved in the Museo di Santa Giulia in Brescia.

The Boethius Diptych was adapted for the liturgy of the Western church in the 7th century. Therefore paintings and memorial inscriptions were added on the interior surfaces.  

Since the 18th century, scholars have studied the diptych and its medieval inscriptions and images. Nevertheless, the diptych was never the subject of a technical art historical study until 2019.

In addition to a microscopic examination, the diptych was photographed in high-resolution and investigated with visible light, ultraviolet fluorescence and infrared reflectography. The carved reliefs, the paintings and the super-imposed layers of inscriptions were examined. With the help of image analysis, nearly unrecognizable details of the inscriptions were made visible.

The diptych shows the consul Boethius standing and sitting, in an ornate toga, opening the games on the occasion of his inauguration as a Roman consul.

This is visible on the slightly concave outer edges and the reduced corners of the plaques, as well as the partly preserved tip of the pulp cavity.

The two ivory panels are connected by a three-part hinge system. Each hinge is made of metal and the pin consists of ivory.

Parts of what must have been the original clasp are visible on the outer edges. One metal knob is still preserved, while on the other panel only a hole reminds of its lost counterpart.

The following imaging techniques were used to examine the painting technique:

Lines incised in the ivory were used to define the contours of the painted frames.
The image was laid out in a detailed underdrawing with brushstrokes in an orange tone.

A white preparation layer was partially applied for the gilding.
Later on, another layer of gold was applied over the remains of the original gilding.

The backgrounds were painted with a bright blue, coarse-grained pigment.
This could be identified as Egyptian blue on the base of VIL images. Due to its aged condition, accumulated dirt and later varnishes, the blue paint layer appears less brilliant today than the reconstruction of the paint layer. In lacunae, the original brilliancy of the blue color can still be seen on the original.

In a later phase of reworking, black contour lines were added to the paintings. This occurred at the same time as the overgilding and served to accentuate outlines and details.

On the basis of the microscopic examination and photographs from the beginning of the 20th century, the original appearance of the paintings could be approximately reconstructed with digital inpainting.

Different phases of the inscriptions could be distinguished with the help of image analysis, allowing most of the inscriptions to be deciphered and dated. This made it possible to draw conclusions about the cultural origin of the persons whose names are mentioned.

The inscriptions were probably added at the same time as the paintings. First, the titulus QVOS DEO OFFERIMUS (“we recommend to God”) was written and the plaques were divided into two columns.

Later, the names and the central vertical divisions were removed so the plaques could be newly inscribed.

The publication of the research results appeared in the Klinger Verlag and can be purchased in bookshops or ordered from the publisher (kontakt@klinger-verlag.de).