The Sagrada Família originated with the Spiritual Association of Devotees of Saint Joseph, founded by bookseller Josep Maria Bocabella amid nineteenth-century Catholic revival and Barcelona's rapid industrial growth. Donations funded an expiatory church dedicated to the Holy Family in the expanding Eixample. Architect Francisco de Paula del Villar designed a conventional Gothic Revival building, and the foundation stone was laid on 19 March 1882. Villar resigned after disagreements, and Antoni Gaudí assumed responsibility in 1883, inheriting a crypt already under construction but radically enlarging the project's architectural and symbolic ambition.

Gaudí transformed familiar Gothic elements through geometry derived from natural growth and structural force. Branching columns, ruled surfaces, catenary models, light wells, and inclined supports were intended to make structure and ornament inseparable. Eighteen towers would represent apostles, evangelists, Mary, and Jesus Christ, while three façades narrated the Nativity, Passion, and Glory. The richly modeled Nativity façade was the principal exterior completed under his direction. Its plants, animals, workers, musicians, and biblical figures connect Christian theology with Catalan landscape and craft rather than presenting nature as mere decoration.

Construction advanced slowly because the church relied on private gifts, and Gaudí repeatedly revised designs as money and techniques changed. In his final years he abandoned most other commissions and lived close to the site. When he died after a tram accident in 1926, only part of the church stood, but workshops held drawings, photographs, plaster models, and geometric studies intended to guide successors. Gaudí was buried in the crypt. His death shifted the project from a personal commission to a contested act of interpretation: later architects had to decide what fidelity to an unfinished, evolving design could mean.

The Spanish Civil War brought the greatest rupture. In 1936 anticlerical attackers damaged the crypt, burned the workshop, and smashed many models. Surviving fragments were painstakingly reassembled, and postwar teams used photographs and published material to reconstruct design principles. Work on the austere Passion façade accelerated in the later twentieth century, with Josep Maria Subirachs's angular sculpture provoking debate because it departed visibly from the Nativity façade. New stone-cutting, engineering analysis, and digital modeling allowed builders to realize complex forms at a speed and scale unavailable to Gaudí.

Pope Benedict XVI consecrated the church and declared it a minor basilica in 2010, even as construction continued overhead. UNESCO recognition applies specifically to the crypt and Nativity façade, added in 2005 to the Works of Antoni Gaudí World Heritage property, not to every later part of the basilica. Visitor revenue now supplies much of the building budget, linking preservation and completion to mass tourism. The COVID-19 shutdown exposed that dependence, interrupting work and overturning timetables tied to the centenary of Gaudí's death.

By the 2020s and 2030s, central towers and remaining architectural elements brought the exterior closer to completion, while sculpture, decoration, and the planned approach to the Glory façade remained longer-term concerns. A proposed monumental stair could require substantial changes to the surrounding neighborhood, setting Gaudí's vision against the homes and businesses that grew while construction stretched across generations. The Sagrada Família is therefore not simply an unfinished masterpiece. It is an active church and urban institution whose meaning lies in continuous negotiation among faith, authorship, technology, tourism, heritage, and the rights of a living city.