This conventional history, however, is mostly gleaned from accounts by Christian authors such as Eusebius. Other sources reveal that there’s more to the story, just as with Constantine’s vision and victory arch. For years after his defeat of Maxentius, for example, Constantine kept making coins that featured Sol, though he eventually stopped around 324. And although Christians observed a rest day on Sunday, in his decree Constantine didn’t refer to it as ‘the Lord’s Day’, as Christians did. He introduced the law ‘in veneration of the sun’. In 330, at his new, supposedly Christian, capital of Constantinople, Constantine erected a giant statue of himself on a 37-metre-high column of purple porphyry. It depicted him naked with a radiate crown, facing east towards sunrise. The statue was felled by high winds in 1106, but literary sources preserve the inscription: ‘For Constantine who is shining like the sun.’
In other words, Constantine didn’t give up his solar beliefs. But how could he follow both religions, when Christianity expressly forbids the worship of other gods? Some clues come from his letters, in which he describes, for example, the saving power of God’s ‘most brilliant beams’, and says that God ‘held up a pure light’ through his son. Historians such as Bardill argue that Constantine never really converted from paganism to Christianity at all. Instead, he simply joined the two, seeing the Christian God as a sort of supreme solar deity whose rays were spread on Earth by Christ. By deliberately blurring the boundaries between the two faiths, he could embrace his new beliefs without having to give up the old.
He wouldn’t have been the first, of course. For centuries, Christians had been drawing on the power and radiance of our star.
•
In the Old Testament, the prophet Malachi refers to the coming messiah as ‘the Sun of Righteousness’; Christ later described himself as ‘the light of the world’. Before Jesus was crucified, his Roman captors mocked him by giving him a radiate crown, made of thorns. But during the first couple of centuries AD, as Christians in the Roman Empire tried to attract followers and distinguish themselves from their parent Jewish faith, they increasingly borrowed the rituals and trappings of sun worship.
Instead of praying towards Jerusalem as the Jews did, they faced east towards sunrise. And instead of keeping the Jewish Sabbath, they moved their main day of worship to Sunday, in line with pagan sun cults. In the second century, the Christian author Tertullian denied that this choice of day had anything to do with its solar connotations. But by Constantine’s time, Eusebius was happy to recognise a direct link, explaining that ‘the Saviour’s day . . . derives its name from the light, and from the sun’.
The major Christian festivals were also scheduled according to the sun’s movements. Easter, the celebration of Jesus’s resurrection, was originally based on the Jewish Passover, itself a direct descendant of the Babylonian new year festival, Akitu, and celebrated on the first full moon after the spring equinox; under Constantine, bishops at the First Council of Nicaea voted to move Easter to the following Sunday. And from at least the fourth century, Jesus’s birth was celebrated on 25 December, the birthday of Sol Invictus, which pagans marked by lighting candles and torches, and decorating small trees.
The result, points out historian and writer Marina Warner, was that Christ’s life became intimately identified with the annual cycle of the sun; his birth is still celebrated just after the winter solstice, when the sun begins to rise towards the spring, and his return from the dead just after the spring equinox, when the sun finally triumphs over darkness and the days last longer than the nights. Other Christian imagery reinforced the metaphor. As early as the first century, the twelve Apostles were widely regarded as representing the twelve signs of the zodiac, through which the sun passes in the sky.
Meanwhile the moon became linked with first, the Church, and eventually the Virgin Mary. In her book Alone of All Her Sex, Warner notes that in the regions where Christianity first took hold, the sun represented ferocious energy and power. It was the gentler moonlight, associated with precious moisture-giving dew, which nourished life. She argues that this inspired the idea of the grace of God mediated through Mary, just as the light of the sun reflects off the disc of the moon. ‘Had Christianity not taken root in the sun-baked east,’ says Warner, ‘the astral images it employs might have been very different.’
Using the sun as a symbol for God made switching to Christianity relatively easy, because converts didn’t have to give up their familiar rituals and festivals. But it also meant that, even as Christians furiously denied links to paganism, with many choosing to die rather than sacrifice to pagan gods, aspects of solar worship were becoming embedded in their faith. As the archaeologist Jacquetta Hawkes puts it: ‘With the malicious irony so often apparent in history, even while they fought heroically on one front, their position was infiltrated from another.’
Constantine took that merging even further, identifying Christ not only with the sun, but with himself. Just as Christ spread divine rays of light on Earth, so did the emperor. One fifth-century description of his sun statue in Constantinople describes how even the city’s Christians laid sacrifices at its base: ‘They venerate it with incense and candles, and they worship it like a god.’ Whether intended or not, Constantine’s original choice to follow Sol was a political ‘masterstroke’. It provided the bridge he needed to link sky worship with Christianity, allowing both pagans and Christians in his empire to unite behind one ruler and one supreme solar god.
This blending had profound consequences not just for Constantine’s image but for how Christians saw their saviour. The earliest known depictions of Jesus come from a private house converted into a Christian church around 235, in the city of Dura-Europos in today’s Syria. Described as the only church walls to survive from before Constantine’s rule, they show a figure in a simple tunic healing a paralysed man; walking on water; tending his sheep. After Constantine’s time, though, typical Catholic depictions were quite different. In the fifth-century church of Hosios David in Thessaloniki, for example, Christ sits on a celestial throne made of rainbows, dressed in purple robes, with a golden halo and his right hand raised.
Although now associated with Christianity, the halo (specifically, a disc behind the head called a ‘nimbus’) was originally used by pagan cults such as Mithraism to depict the divine nature and radiance of the sun god. Then Constantine depicted himself with one on his victory arch in Rome, a first for a Roman emperor. Only after that did Christians start using halos too, and in doing so triggered a transformation in which Christ took on more and more imperial features. Thanks to Constantine, the humble teacher became a cosmic emperor, ruling over the universe with the radiance of the sun.
It’s an image that remained powerful throughout the Middle Ages. Scholars argue about whether Christians who borrowed the halo intended to show their messiah as a powerful emperor, or whether they simply hoped to communicate the radiance and lucidity of the sun. Either way, once it was adopted, the image took hold, says the art historian Thomas Mathews: ‘He became what people pictured him to be.’
•
Worship of the sun and stars didn’t just shape ideas about Jesus Christ. It is also at the root of modern western beliefs about heaven and the fate of human souls. In a children’s book called What’s Heaven? author and former First lady of California Maria Shriver describes the afterlife as ‘a beautiful place where you can sit on soft clouds . . . when your life is finished here on earth, God sends angels down to take you to heaven to be with him.’ The idea that after we die our disembodied souls float up to live with angels in the sky is popular among many Christians today. It would have shocked the ancient Israelites.
According to Judaic historian J. Edward Wright, people in ancient Israel believed – as Palaeolithic and Neolithic societies seem to have done – that the cosmos had three tiers: a flat Earth with the underworld beneath it and the sky above. The Hebrew Bible (repurposed in the Christian Old Testament) describes the sky as a tent or canopy stretched over the Earth, but also as a solid ‘firmament’, with a stone floor and storehouses for meteorological phenomena such as wind, snow and hail. These descriptions use the imagery