Dome by Vincenzo Foppa (?)

Vincenzo Foppa (?)

Dome, c.1462–68, Fresco, Portinari Chapel, Basilica of Sant'Eustorgio, Milan, akg-images / Mondadori Portfolio / Mauro Ranzani

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‘Like a Rainbow’

Commentary by
Read by Lydia Ayoade

The Cappella Portinari was erected in the mid-fifteenth century at the north-east of the Dominican church of Sant’Eustorgio in Milan. Commissioned by the wealthy banker Pigello Portinari, it became the patron’s funerary chapel at his death in 1468. Upon entering the chapel, the viewer is enraptured by the expanse of its dome, richly ornamented with four bands of colour, arranged concentrically around the lantern at the summit. 

This painterly decoration invites discussion in relation to contemporaneous understandings of the rainbow in natural philosophy and theology. By the fourteenth century, experts on perspective and meteorology tended to agree that the rainbow comprised four colours: red, yellow, green, and purple or blue, arranged in this order. The dome of the Portinari Chapel features these colours, disposed precisely in this sequence, indicating that its decorative program was indeed intended to be understood as a rainbow.  

Based on Genesis 9:12–13, medieval theologians conceived of the rainbow as an intermediary between heaven and earth, and as a reminder of God’s benevolence towards his creation. This connotation was both sustained and complicated by the book of Ezekiel (1:28) and Revelation (4:3), where the image of the rainbow expresses the radiance of God’s glory. While the Genesis passage unambiguously identifies the arcus in the sky as a token of covenant and protection, Ezekiel’s and John’s visions are more ambivalent. The rainbow still manifests divine presence, but its appearance—which eminent medieval theologians, including Isidore of Seville (De Natura Rerum) and Hrabanus Maurus (De Universo), interpreted as evocative of the Last Judgement—is more fearsome than reassuring.  

In its dual meaning as token of divine benevolence and reminder of the judgement that awaits all souls, the iridescent cupola of the Cappella Portinari infuses the space with explicit eschatological connotations. These were consistent with the original function of the chapel as a funerary shrine, and also offered a flexible canvas for the theological and scientific reasoning of the Dominican friars of Sant’Eustorgio. 



Gitlin Bernstein, JoAnne. 1981. ‘Science and Eschatology in the Portinari Chapel’, Arte Lombarda, 60: 33–40

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