Bramante's Tempietto: the perfect circle on the site of martyrdom

At San Pietro in Montorio Bramante built a small circular temple: its history, uncertain dates and the symbolism of the circle in Renaissance Rome.

In the courtyard of a convent on the Janiculum hill in Rome stands a building so small that it can almost be taken in with a single glance from one point. It has a circular plan, a Doric colonnade all round, a drum and a dome. Yet the Tempietto of San Pietro in Montorio, the work of Donato Bramante, is regarded as one of the manifestos of High Renaissance architecture, the point at which Roman antiquity is reborn as a Christian form.

The site and the patrons

According to a medieval tradition, the apostle Peter was crucified upside down on the Janiculum. The sovereigns of Spain, Ferdinand of Aragon and Isabella of Castile, financed the rebuilding of the church and convent of San Pietro in Montorio, entrusted to Spanish Franciscans. In the courtyard the Tempietto was erected as a martyrium marking the spot where the cross was believed to have been planted.

The dating is debated. An inscription in the crypt gives the year 1502, but many historians believe that construction took place a few years later, in the first decade of the sixteenth century. It is one of those cases in which the carved date may refer to the foundation or dedication rather than to the completion of the work.

The language of the circle

The Tempietto takes up the form of ancient circular temples, such as that of Vesta at Tivoli or the round temple in the Forum Boarium. Sixteen granite Doric columns support an entablature whose metopes are decorated with liturgical objects and Petrine symbols, such as the keys. The Doric order, which Vitruvius's treatise associated with strong and masculine deities, was a fitting choice for a martyred apostle.

For the Neoplatonic culture of the Renaissance the circle was the image of divine perfection, without beginning or end, equally distant from the centre at every point. To build a circular building meant to evoke the order of the cosmos and the very nature of God. The Tempietto translates this idea into stone with a purity that contemporaries immediately perceived as exemplary.

A model for the centuries

Sebastiano Serlio published in his third book on architecture, issued in 1540, a design in which the Tempietto was to be surrounded by a courtyard that was also circular, never built. Andrea Palladio, in the Four Books of Architecture of 1570, placed it beside the temples of antiquity, the only modern building to receive this honour. It is an eloquent recognition: for Palladio, Bramante had attained the dignity of the ancients.

Since then the form of the Tempietto has generated a very long line of descendants, from the domes on colonnaded drums of many Baroque churches to nineteenth-century civic buildings in Europe and America. The dome of St Peter's itself, in Bramante's design and later in Michelangelo's, shares with the small martyrium on the Janiculum the dream of a perfect centre.

To visit the Tempietto today is to stand before an idea rather than a monument. Its small size compels one to walk around it, to observe its proportions up close, to go down into the crypt where the place of the cross is shown. One then understands how a minimal architecture can contain a vision of the world, in which the memory of Christian martyrdom and the geometric perfection of the ancients become one and the same.