La Sagrada Familia: general view

The Templo Expiatorio de la Sagrada Familia is Gaudí's masterpiece, and, although only partially completed, it is among the most impressive buildings of the 20th century. He took charge of the works at the age of 31 and continued for the rest of his life; it thus summarizes his evolution as an architect as well as the deepening of his spiritual conviction, measured in terms of his increasing dedication to the task.

The project was initiated by the Asociación de Devotos de San José, founded in 1866 to raise funds to build a church dedicated to St Joseph and the Holy Family. This concept was widened to become a cathedral for the new metropolitan areas of Barcelona, and del Villar's neo-Gothic design had been under construction for more than a year when Gaudí took over in 1883.

Gaudí completed the crypt to del Villar's design in 1891 but began to work on a more grandiose concept for the whole church, including an encircling ambulatory or cloister. By 1893 he had completed the walls and finials of del Villar's apse and had started work on the façade of the Nativity: this is where Gaudí's own conception of the structure began to appear, dominated by towers. The triple portals (1903) of the façade, representing Faith, Hope, and Charity, rise out of the ground as neo-Gothic elements but are increasingly clothed and then draped in natural forms until the angular Gothic gables are almost concealed by carvings that hang like canopies of stalactites over the porches. This eases the transition through Modernisme to the mature individualism of the four great towers named after the Apostles: from south to north, Barnabas, Simon, Thaddeus, and Matthew. Only Barnabas was completed before Gaudí's death.

The towers of the Sagrada Familia, which were to house tubular bells, are square at their bases, but above the portals, they become cylinders pierced by spirals of columns and narrow, round-headed arches. For acoustic reasons, the perforation was continued as the stone columns converged in a series of tall, slender parabolic arches, tied together by thin plates in spirals that produce a ladder-like effect. Above the arches are hexagonal pinnacles; above them are Cubist faceted finials covered with polychromatic Venetian glass mosaics, each surmounted by a three-dimensional haloed cross. The towers and the church show Gaudí's structural aesthetic at work in the idiom of the Gothic cathedral, eliminating the need for flying buttresses. At the same time, his polychrome decoration that had its roots in Oriental traditions provided both the natural motifs inspired by Ruskin and the religious iconology of the church.

For all the virtuoso qualities of the church, however, the little school (1909) built by Gaudí on the site of the Sagrada Familia perhaps best crystallizes the essence of his genius. It has an undulating roof built of bovedas tabicadas (Sp.: tile vaults), a technique later developed and widely used in the USA by Rafael Guastavino, and walls that are both curved in plan and inclined outwards from the roof to counteract thrust. It is a simple statement of his aesthetic, expressing nature through form, and of his practical genius in adapting traditional materials and methods through the application of contemporary building technology. Gaudí died a few days after being knocked down by a trolley bus on his way to church, leaving behind him unexecuted drawings for the Sagrada Familia, for the remaining main façades, the crossing, and a chapel of the Assumption. He also left behind a body of work that continued to influence an extraordinarily diverse following including Surrealists, Abstract Expressionists, engineers, and environmentalists.