Ildefonso Cerdá Suñer (1815-1876) was the progressive Spanish Catalan urban planner who designed the 19th-century "extension" of Barcelona called Eixample.
He originally trained as a civil engineer. When the Spanish government of the time finally gave in to public pressure and allowed Barcelona's city walls to be torn down, he realized the need to plan the city's expansion so that the new extension would become an efficient and livable place, unlike the congested, epidemic-prone old town within the walls. When he failed to find suitable reference works, he undertook the task of writing one from scratch while designing what he called the 'Eixample', borrowing a few technological ideas from his contemporaries to create a unique, thoroughly modern integrated concept that was carefully considered rather than whimsically designed.
He continued to create projects and improve existing designs throughout his lifetime, as well as to develop his theories taking on larger planning scopes (at regional planning level), until the very end. In the process, he lost all his family's inheritance and he died a heavily indebted near-pauper, never having been paid for his chief masterpiece, the design of the Barcelona 'Eixample'.