Alcalá de Henares possessed a scholarly tradition before its celebrated university city took form. King Sancho IV authorized a studium generale there in 1293, but the decisive transformation came two centuries later through Cardinal Francisco Jiménez de Cisneros, archbishop of Toledo and a powerful reformer in the Catholic monarchy. Papal bulls issued by Alexander VI in 1499 authorized Cisneros's new institution. He imagined not a single building but a planned academic community of colleges, streets, chapels, presses, lodgings, and services integrated into the existing Castilian town.

Cisneros called the project a City of God devoted to education, clerical reform, and the study of languages and theology. The Colegio Mayor de San Ildefonso formed its institutional center, accompanied by smaller colleges designed for students from different regions and backgrounds. Its famous stone façade, completed in the sixteenth century under Rodrigo Gil de Hontañón, presents scholarship through an elaborate Renaissance vocabulary of coats of arms, saints, classical ornament, and imperial symbolism. The university chapel holds Cisneros's monumental tomb, while courtyards and arcades organized collective routines of study, worship, and debate.

The university became known by the Latin name Complutum and attracted leading figures of Spain's Golden Age. Its scholars produced the Complutensian Polyglot Bible, a landmark edition presenting biblical texts in Hebrew, Greek, Latin, and Aramaic. Completed in the 1510s and authorized for circulation in the following decade, it embodied Cisneros's belief that religious learning required direct engagement with original languages. Humanism, medicine, law, theology, and literature flourished in Alcalá. The city's printing houses spread books widely, while its intellectual reputation influenced later Spanish foundations and university planning across the Atlantic.

Alcalá's history was never limited to classrooms. Its urban fabric included the archbishop's palace, churches, convents, Jewish and Muslim legacies, markets, and the houses of craftspeople who sustained university life. Miguel de Cervantes was born in Alcalá in 1547, binding the city to Spanish literary memory even though he was not a recorded student of the university. Students and townspeople sometimes clashed, and academic privilege existed within a hierarchical society. The precinct nevertheless created an unusually close relationship between civic identity and a purpose-built landscape of learning.

Decline accelerated in the eighteenth and nineteenth centuries as reforms weakened the collegiate system. In 1836 the historic university was transferred to Madrid, and in 1845 its Alcalá properties were auctioned. Demolition or dispersal appeared likely until local residents formed the Society of Co-owners, later known as the Condueños, in 1851. They purchased major buildings collectively to protect them until higher education might return. Military, religious, and other uses altered the fabric, but this remarkable civic intervention prevented the core of San Ildefonso from being lost.

The modern University of Alcalá was created in 1977 and gradually reoccupied restored historic buildings, renewing the town's academic purpose after more than a century. UNESCO inscribed the University and Historic Precinct in 1998 as the first planned university city of the early modern era and a model with wide international influence. Preservation now joins active teaching, tourism, and city life rather than presenting an empty campus museum. Alcalá's importance rests in that continuity of idea: institutions may move or collapse, yet a community can safeguard architecture until learning gives it meaning again.