26 Ezequiel Uson Guardiola, José Antonio Gárate Alcalde, Víctor Jørgensen-Mínguez, Eva Espuny Camacho
Two of the six children of the German architect, Simón
and Diego, were also magister operis architects, and the
former achieved a relevance comparable to that of his fa-
ther. Simón de Colonia (c. 1450–1511) is a key gure in
late Gothic architecture in Burgos. His production is char-
acterized by the introduction of innovative ribbed-open-
work vaults and by the great prominence of sculptural
decoration. He trained in his father’s workshop, succeed-
ing his father as master builder of the cathedral from 1481
onwards and taking charge of completing the projects that
the latter had begun before his death, such as the chapel of
the Conception in the Cathedral of Burgos or the church
of the Cartuja de Miraores (Justi 1913).
Between 1482 and 1494 he built what is considered his
great masterpiece, the Chapel of the Purication or the
Constable. In it he executed a spectacular openwork vault
that would be widely imitated in Burgos architecture well
into the 16
th
century.
In the city of Burgos he also built the Casa del Cordón
(the urban palace of the Constables of Castile), and worked
on the churches of San Nicolás and San Gil. Outside Bur-
gos, the cloister of the monastery of San Salvador de Oña
and the façades of the churches of Santa María de Aranda
de Duero and the convent of San Pablo in Valladolid stand
out (Payo-Hernanz, Matesanz del Barrio 2015).
The architects of the so-called Colonia workshop are
particularly known for their ability to incorporate surpris-
ing lighting eects into their works (Sánchez-Ameijeiras
2001). The phenomenology of light was of great impor-
tance in the medieval Christian imagination. In this sense,
the Colonia workshop has bequeathed to posterity the hie-
rophanies visible in the churches of San Juan de Ortega,
Santa María de Miraores and San Nicolás de Bari, all
of them located in the city of Burgos and/or its surround-
ings. These lighting eects, popularly known as “miracles
of light”, always occur on specic dates in the liturgical-
astronomical calendar.
The chapel of the Conception of the Virgin
of the cathedral of Burgos
The premise of this research is that, in addition to the
three churches mentioned, these same lighting eects were
produced in the Chapel of the Conception of the Virgin
(Fig. 1) of the cathedral of Burgos until the chapel of Santa
Tecla was built in the 1
st
half of the 18
th
century, attached
to its southwest side, and, as a consequence, the source of
natural light that caused them was blinded, an oculus locat-
ed in the highest part of the southwest wall, just in front of
the main altarpiece of the chapel (Figs. 2a, b, 3)
1
.
As we have demonstrated using solar simulation soft-
ware, before the oculus was blinded in the 18
th
century,
a beam of sunlight penetrated through it during the spring
and autumn equinoxes and travelled diagonally across the
main altarpiece, from left to right and from bottom to top,
briey illuminating its main theme, the embrace of Saint
Joachim and Saint Anne, the parents of the Virgin Mary,
before the Golden Gate of Jerusalem.
The Chapel of the Conception of the Virgin, located in
the Gospel nave of the cathedral, next to the north arm of
the transept, began to be built in 1477 by order of Luis
de Acuña y Osorio, Bishop of Burgos between 1456 and
1495, with the intention of converting it into his funeral
chapel, just as his predecessor, Alonso de Cartagena, had
done a few years earlier in the south arm of the transept
with the Chapel of the Visitation (Martínez-Sanz 1866).
Although there is no documentary evidence to conrm
this, the construction of the chapel of the Conception has
traditionally been linked to Juan de Colonia, who is said to
have been in charge of the works until his death. Later, his
son Simón, after redesigning the initial project was respon-
sible for completing it (Menéndez-González 2009).
The chapel has an irregular rectangular oor plan cov-
ered by two sections of complex tierceron vaults. The con-
struction had to adapt to the peculiarities of a space that was
highly conditioned by the presence of the buttresses of the
side nave and the northern arm of the cathedral transept, as
well as by the layout of the current Fernán González Street.
The chapel opens onto the gospel nave through two large
pointed arches, which in turn are closed with two railings
from the period. The space was illuminated through three
openings to the outside, two pointed windows to the north-
west and southeast and the aforementioned oculus to the
southwest.
But this chapel is best known for its extraordinary altar-
piece, the work of Gil de Siloe (sculpture) and Diego de
la Cruz (polychromies), who executed it between 1483
and 1486 (Fig. 4). It is a very novel altarpiece for Cas-
tile at the time, both for its structure and its iconography.
It features the monumental Tree of Jesse, or genealogical
tree of Christ, located in the central street, whose branches
ascend the altarpiece surrounding the large rectangle that
frames the main theme, the Embrace before the Golden
1
To build the chapel of Santa Tecla, four small medieval chapels
that faced the gospel nave of the cathedral and the parish church of
Santiago de la Fuente, which was located behind them, were demol-
ished.
Fig.1. The Cathedral of Burgos, Spain.
View of the entrance to the Chapel of the Conception of the Virgin
(photo by J.A. Gárate-Alcalde)
Il. 1. Katedra w Burgos, Hiszpania.
Wnętrze – widok na wejście do kaplicy Poczęcia NMP
(fot. J.A. Gárate-Alcalde)
