The first extended study of urbanism is generally credited to Ildefons Cerdá (1815-76), the civil engineer responsible for designing the plans to extend Barcelona beyond the confines of its constrictive medieval walls. In 1855 he made an initial proposal, which was revised in 1859. This revised plan was implemented, giving rise to the district of Example (meaning extension). His characteristic chamfered corner. He later proposed another revised plan.
Cerdá was surprised to learn that no scientific literature existed on the study of proper urban design and planning. As a result of his preliminary studies of Barcelona’s needs and challenges, in 1859 he published a study called Teoría de la Construcción de Ciudades (The Theory of City Construction), which is widely considered the first text in modern city planning. He later published additional studies, most notably in 1867 his Teoría General de la Urbanización (A General Theory of Urbanization). Despite this pioneering work, his work was little known, even in the Spanish-speaking world. His General Theory was not published in English until 1999.