Italian architect and theorist. He was accepted as a Theatine novice in 1639, spent his novitiate at the monastery of San Silvestro al Quirinale in Rome, and returned to Modena in 1647, where he was ordained in 1648. He became provost in 1654. He left Modena and became a member of the Theatine House of Parma in 1656 and apparently visited Prague and Lisbon before publishing his play La Pieta trionfante in Messina in 1660, where he was a lecturer in mathematics. He wrote four mathematical books in both Latin and Italian, of which Euclides adauctus is a work on descriptive geometry. In 1665, he published a mathematical-philosophical tract Placita Philosophica defending the geocentric universe against Copernicus and Galileo. He designed a large number of public and private buildings in Turin, including the palaces of the Charles Emmanuel II, Duke of Savoy, the Royal Church of San Lorenzo, most of the Chapel of the Holy Shroud (housing the Shroud of Turin; begun in 1668 by Amedeo di Castellamonte), the Palazzo Carignano, the Castle of Racconigi and many other public and ecclesiastical buildings at Modena, Messina, Verona, Vienna, Prague, Lisbon, and Paris. The Palazzo Carignano is regarded as one of the finest urban palaces of the second half of the 17th century in Italy. Guarini appears to have been influenced by Borromini. Between 1657 and 1659 he stayed in Spain, where he studied Moorish buildings; this influenced the style of some of his buildings in Turin. Together with Francesco Borromini, Guarini is considered the best exponent of the anti-classical, anti-Vitruvian trend prominent in Italian architecture after Michelangelo but increasingly less popular from the late 17th century. His architectural designs are noted for their subtlety and daring and complex domes but were ignored in Italy outside Piedmont. Illustrations published in 1686, however, and again in Guarini's treatise "Architettura civile" were highly influential on the development of south German and Austrian late Baroque and Rococo architecture. In Guarini's work we see the end of the classical formats which were predominantly intended for spatial arrangements. At the same time Guarini was the precursor of a form of modern architecture which no longer gave pre-eminence to a representation of space, but stressed the skills of creating internal space and of construction. //