SKY OF SALAMANCA

The 15th century marked a period of splendor for the University of Salamanca with the influx of a large number of students and the birth of the printing press, which considerably increased the number of books that reached the university. It was in this context that the Library was built in the Escuelas Mayores (Main Schools). Thanks to the preserved documentation, we know that the construction of the library was carried out by masters Yuçca and Abrayme between 1474 and 1479. However, the cloister books that would allow the authorship and chronology of the astrological program painted on its vault to be known with certainty are not preserved. The authorship was attributed by Gómez Moreno to the painter Fernando Gallego, who would have executed it between 1483 and 1486.

This first library was built over the old chapel. It was a rectangular room approximately 23 meters long by 8.70 meters wide. Its roof consisted of a brick barrel vault, supported and divided into three sections by two ashlar arch bands. At both ends, the structure was topped with octagonal vaults.

The earliest references date from the late 15th century and are attributed to Lucio Marineo Sículo and Jerónimo Münzer. The most complete description was made by Diego Pérez de Mesa in 1595, who noted that the original vault depicted the 48 Ptolemaic constellations: twelve zodiacal, twenty-one boreal, and fifteen austral. The presence of the Sun and Mercury, along with Marineo and Münzer's descriptions, indicates that the other planets known at the time were also featured: the Moon, Venus, Mars, Jupiter, and Saturn.

Between 1503 and 1506, the university renovated the chapel, installing a new altarpiece that encroached upon the library space. A new library was then built in the western gallery. When the coffered ceiling that served as the library's floor and the chapel's ceiling was dismantled, the celestial vault came to directly cover the chapel until the mid-18th century. These modifications, coupled with damage caused by humidity, severely deteriorated the painting. To preserve it, a restoration led by Juan de Yprés was undertaken, whose repaints, incompatible with the original pigments, ended up further damaging the work.

In 1763, a new renovation caused two of the three sections of the vault to collapse, with only the section at the foot of the chapel being preserved. A new vault was then built, which concealed the paintings for centuries. The work then fell into oblivion until its rediscovery in 1901 by Professor García Boiza. In 1913, the historian Manuel Gómez-Moreno attributed the paintings to Fernando Gallego, an identification accepted ever since by all researchers who have studied this work. Gallego is believed to have created the work between 1483 and 1486 as a representation of the known universe, based on Ptolemaic cosmology and the illustrations of Hyginus's Poeticon Astronomicon (1482). Its function was both didactic —to show visible constellations and planets— and spiritual, by linking celestial order with divine harmony.

In the 1950s, the paintings were removed from the original vault using the strappo technique and transferred to canvas to ensure their preservation. The delicate operation was carried out by the Gudiol Ricart brothers, and in 1952 the already restored fragment was installed in a room in the Escuelas Menores (Minor Schools), where it remains today.

Since its recovery, various researchers have raised the possibility that the Sky of Salamanca represents a specific astronomical configuration. It has been suggested that it might correspond to the sky on an August night in 1475, although this hypothesis has not been confirmed. In any case, the work fully reflects the spirit of the Renaissance, integrating science, art, and religion into a visual expression of extraordinary beauty and profound meaning.

The rediscovery of the mural paintings that decorated the vault of the first university library took place at the beginning of the 20th century, although it wasn't until the middle of that century that it was decided to restore and exhibit them to the public.

In 1950, the Gudiol brothers were commissioned to extract the mural paintings for their restoration and transfer to a new location in the Escuelas Menores. Using the strappo technique, the paintings were transferred to canvas and divided into 33 fragments, which were mounted on wooden stretchers. Finally, they were placed in a similar arrangement to the original, of which only the octagonal section at the foot of the chapel and one of the transverse arches had been preserved.

Thanks to the testimonies of those who were able to contemplate the work in its entirety, researchers have concluded that it featured the seven planets known at the time, along with the 48 constellations of the eighth sphere: 21 northern, 15 southern, and 12 zodiacal, in addition to the four cardinal winds. Against a blue sky sprinkled with golden stars, various allegorical figures of celestial bodies, planets, and constellations from both hemispheres and the signs of the Zodiac are displayed. A mixed technique was used in its creation: oil for the figures and tempera for the rest.

From the original ensemble of the Salamanca Sky, two of the seven planets represented are preserved: • Sun (Helios): appears as a beardless youth, crowned with rays, dressed in Gothic attire. He is mounted in a quadriga drawn by three white horses and one black, carries a scepter, and heads towards his diurnal house, Leo, whose figure is represented on the chariot wheel.

• Mercury: is shown seated in a chariot drawn by two eagles, on his way to his nocturnal abode, Virgo. He carries the caduceus and a star on his chest. His two astrological dwellings, Gemini (diurnal) and Virgo (nocturnal), are depicted on the chariot wheels. Beneath these planetary figures are three large representations of northern constellations: Boötes, Hercules, and Ophiuchus.

To the right of the mural, several southern constellations are distinguished: Hydra – more than 7 meters long – appears represented as a large serpent, but without showing the seven heads of the mythological model, Corvus, Crater (or Urn), Robur (the Oak), Ara, Corona Australis, and Centaurus.

Regarding the zodiacal constellations, five signs corresponding to the second half of the year have been preserved: Leo, Virgo, Libra, Scorpio, and Sagittarius.

The ensemble is completed by the personification of the four cardinal winds: Zephyrus, Auster, Eurus, and Boreas, represented as human heads with swollen cheeks, blowing and animating the movement of the cosmos.

Finally, the semi-circular arch framing the scene displays, in golden letters on a blue background, a stanza from Psalm 8: “Videbo celos tous opera digitorum tuorum lunam et stellas que tu fundasti.” (“I will contemplate the heavens, the work of your fingers, the moon and the stars which you have created.”)