24
conceived (Barton, 1995; González García et al., 2019). Hence temples and cities
throughout the empire were orientated accordingly.
Most interesting is the case of the Augusteum at Narona (Fig. 9) since its orientation (δ ~ 0½°) would confirm the possibility that this suggestive monument was
built in commemoration of Augustus’ 75th birthday, and accordingly aligned
(Belmonte, Rodríguez-Antón, & González-García, 2020).
When Christianity ruled over the Roman Empire, the new religion assimilated
several concepts of Roman culture. Christmas was assimilated to the birth of the
Unconquered Sun in the night from December 24th to 25th and hence, Jesus conception was assumed to be 9 months earlier at the Roman spring equinox at March
25th. This was assimilated as the Feast of the Annunciation. In this sense, church
alignments in the Iberian Peninsula followed certain specific rules throughout the
early Middle Age. In particular, a vast majority of churches tended to be orientated
with the apse facing sunrise on the vernal equinox, taking this as March 25th. This
prescription seems to have been followed for almost a 1000 years and can be
observed in the shift of the main maximum in the orientation histograms through the
different time periods. Such a shift is due to the drift of the Julian calendar in relation to the seasons (González García & Belmonte, 2015). For example, for
Mozarabic churches (Fig. 10), the architectural style used in the Christian territories
of the Peninsula just before the arrival of Romanesque, the maximum of the
declination histogram was at c. 4°, corresponding to March 30th, Gregorian proleptic (or March 25th, 1050 AD, Julian).
Fig. 10 Azimuth histogram for the orientation of 167 pre-Romanesque churches across the Iberian
Peninsula (inset: the Mozarabic church of San Juan de Busa, Huesca). The largest concentration of
orientations is towards the eastern half of the horizon with a maximum at due-east. Diagram
adapted from González García and Belmonte (2015)
J. A. Belmonte
conceived (Barton, 1995; González García et al., 2019). Hence temples and cities
throughout the empire were orientated accordingly.
Most interesting is the case of the Augusteum at Narona (Fig. 9) since its orientation (δ ~ 0½°) would confirm the possibility that this suggestive monument was
built in commemoration of Augustus’ 75th birthday, and accordingly aligned
(Belmonte, Rodríguez-Antón, & González-García, 2020).
When Christianity ruled over the Roman Empire, the new religion assimilated
several concepts of Roman culture. Christmas was assimilated to the birth of the
Unconquered Sun in the night from December 24th to 25th and hence, Jesus conception was assumed to be 9 months earlier at the Roman spring equinox at March
25th. This was assimilated as the Feast of the Annunciation. In this sense, church
alignments in the Iberian Peninsula followed certain specific rules throughout the
early Middle Age. In particular, a vast majority of churches tended to be orientated
with the apse facing sunrise on the vernal equinox, taking this as March 25th. This
prescription seems to have been followed for almost a 1000 years and can be
observed in the shift of the main maximum in the orientation histograms through the
different time periods. Such a shift is due to the drift of the Julian calendar in relation to the seasons (González García & Belmonte, 2015). For example, for
Mozarabic churches (Fig. 10), the architectural style used in the Christian territories
of the Peninsula just before the arrival of Romanesque, the maximum of the
declination histogram was at c. 4°, corresponding to March 30th, Gregorian proleptic (or March 25th, 1050 AD, Julian).
Fig. 10 Azimuth histogram for the orientation of 167 pre-Romanesque churches across the Iberian
Peninsula (inset: the Mozarabic church of San Juan de Busa, Huesca). The largest concentration of
orientations is towards the eastern half of the horizon with a maximum at due-east. Diagram
adapted from González García and Belmonte (2015)
J. A. Belmonte