Jujol was born in 1879 in Tarragona, in about the most fitting place imaginable for a future architect of light and pattern: the top floor of a public school. His father, Andreu Jujol, ran the Sant Joan school, and the family lived above the classrooms for nine years. The boy drew constantly. He wandered the hills around the city and clambered over its Roman ruins, absorbing an admiration for nature that never left his work. When he was nine, in 1888, his father's post moved the family to Gracia, then a town of its own and now a district of Barcelona. Five years later they moved into the city proper, where Jujol walked the medieval streets and taught himself to draw the Gothic buildings stone by stone. Accepted into Barcelona's architecture school in 1901, he apprenticed under Antoni Maria Gallissa, a mentor he revered, decorating a street for the city's Mercè festival with hand-wrought metal frames and stained glass. Later he joined the studio of Josep Font i Gumà and helped craft the Trinity altar in the basilica of Santa Maria del Mar.

He qualified as an architect in 1906, the same year he met Gaudí through a mutual friend, Dr. Santaló. The partnership was immediate and lasting. Their first project together was Casa Batlló, where Jujol worked on the building's ceramic facade and its first floor; at Casa Milà, the rippling apartment block Barcelonians nicknamed la Pedrera, he shaped the rooftop chimneys and the plaster bands framing the doors. Then came Park Güell, where between 1911 and 1913 he covered the benches and ceilings in trencadis, the technique of setting shattered tile and glass into flowing mosaic. His biographers suspect he pushed Gaudí toward bolder color and freer form, though the master never said so outright. What is certain is that Gaudí, famously particular, trusted Jujol with his most visible surfaces for years. Jujol had a signature of his own, too: the sgraffito he scratched into plaster, a decorative trick he made unmistakably his.

Jujol's imagination ran past what patrons would pay for. As a young draughtsman he drew up plans for an amusement park modeled on the Solar System, a whirling scheme that was never built and never revived. His most personal work met a slower fate. In the mid-1920s he began a sanctuary to Our Lady of Montserrat on a hill at Montferri, near his native Tarragona, a fantasia of some 120 parabolic arches whose jagged silhouette deliberately echoed the serrated peaks of the real Montserrat massif. He built it from prefabricated pieces of local stone and cement, cast on site. Money ran out, the Spanish Civil War intervened, and the work stopped. Jujol died in Barcelona in 1949 without ever seeing it finished.

The story did not end at his death. In 1984, decades after Jujol was gone, builders returned to the hill at Montferri and took up his drawings again. They completed the sanctuary in 1999, pale and spiky and strange, rising from the vineyards like a smaller, wilder cousin of the Sagrada Família. Across Catalonia, his fingerprints are everywhere once you learn to see them: the whimsical towers he raised in Sant Joan Despí, the ceramics of Casa Bofarull, the country churches near Tarragona. For a long time he was treated as a footnote to Gaudí. He is now recognized for what he was, one of the most inventive and least classifiable talents that Modernisme ever produced.