The lessons he learnt in Brittany — spiritual symbolism, simplification, colour liberated from representation — found even more scope in Tahiti. It was there that his work achieved its most poetic form. Gauguin was adamant that his aesthetic was distinct: "I have always said...that the literary poetry of the painter was special and not the illustration or translation into forms of written texts." His special poetry was to conjure up, through colour notes that act like musical notes, a prelapsarian paradise. In a heady realm of dreamy young girls (men hardly ever feature) and vivid foliage ancient gods sit on the windowsill or the foot of the bed, they are there in wall carvings and they haunt the rivers and forests. They watch over eating and drinking, sex and sleep, sentinels between the spiritual and the temporal.  

The erotic lassitude was, of course, another myth. Just as the Brittany Gauguin had painted bore no resemblance to the hardscrabble late 19th-century reality, so by this time his Tahitian Venuses wore Western smocks and missionaries had ensured that the god they worshipped was Christian. And the painter, as he was aware himself, was the serpent in his own Eden — a drunk and a sexual predator, a morphine addict and near-invalid little loved by the villagers he lived among. His genius, however, was to make the myth correspond with our communal imaginings. So potent was it that it is no surprise he believed it himself.

It is not just Britain's Catholics who are the beneficiaries of Pope Benedict XVI's visit last month. In an ecumenical act of grace he has facilitated the loan of four of the Vatican's magnificent Acts of the Apostles tapestries. They are hanging, until October 17, in the Victoria and Albert Museum alongside the seven Raphael cartoons from which they were woven. This is the first time since 1516-1521, when the tapestries were made in the Flanders workshop of Pieter van Aelst, that both cartoons and weavings have been in the same room. Together these precious objects represent one of the high-water marks of the Renaissance.

It is worth remembering that in the 16th century tapestries were far more valuable than paintings: these de luxe creations in wool, silk and gilt-metal-wrapped thread took teams of highly-skilled workers hundreds of hours to create. 

Their sheer expense is one reason why Pope Leo X commissioned Raphael, the most fashionable artist of the day, to design 10 tapestries to hang in the Sistine Chapel. They were his response to the patronage of his papal predecessors Sixtus IV and Julius II that had made the Chapel the most artistically elevated space in Christendom. Even then these monumental depictions of the lives of St Peter and St Paul were only in situ on occasions of great liturgical pomp. 

While the passage of 500 years has taken a heavy toll on their colours, their full majesty is still easy to imagine. The opportunity to compare the tapestries with Raphael's compositions will probably never come again. That they are together at all is a minor miracle and reason enough to give thanks.