Europe in the 17th century, and in particular Roman Catholic Europe, revels in a new artistic style embracing architecture as well as painting and sculpture. In many contexts, such as church interiors, the baroque combines all three arts in an unprecedented way to create a sense of emotional exuberance.

This mood is very different from the dignified and often severe masterpieces of the Renaissance. The term barocco is first used to suggest disapproval. It is thought to derive from a Portuguese word for a misshapen pearl. Certainly unbalance and excess are the qualities which baroque artists indulge in and turn to advantage.

The Roman Catholic world is the natural home of baroque, because its mood suits so well the message of the Counter-reformation. Protestant reformers can be caricatured, not too unreasonably, as argumentative, dour, unsentimental, hostile to images, and distrustful of any authority except that of holy writ.

The Catholic church by contrast enjoys an aura of centuries of authority and prestige, has long used art and music with great skill to touch the emotions of the faithful, and much prefers a good show to a good argument.

Following the example of the new St Peter's in Rome, numerous churches built and decorated in the 17th century put baroque at the service of the church's message. The faithful are welcomed by rows of saints, gesticulating eagerly in stone from alcove or roof line.

Inside a baroque church, light falls on mingling curves of columns and altars and sculpted groups, breaking up the solidity of side walls and often leading the eye up to an illusionistic ceiling - in which angels and people of fame or virtue stream upwards into the distant clouds of heaven. There is nothing half-hearted about baroque (at any rate until a slight loss of nerve in the 18th century results in the development known as rococo).