When talking about Barcelona urban planning, we must start with Ildefons Cerdà. This Catalan (Catalunya) civil engineer, urban planner and social activist who was born in 1815 and died in 1876 established an impressive reputation that often appears in Barcelona city promotional videos and various tourist souvenirs. of octagonal grid-like urban fabric. Ildefons Cerdà was born into a wealthy family in a town near Barcelona. After graduating with an engineering degree in 1841, he has been committed to presiding over the construction of municipal projects in Spanish cities such as Barcelona, ??including the planning of streets, water supply and drainage, and telecommunications networks. After the death of his father and brother, Cerdà inherited the family property. He became an active political activist and worked hard to realize his ideal city. His famous urban plan for Barcelona, ??the so-called "Plan Cerdà", was implemented in 1859, but was designed as early as 1854. In 1854 in Barcelona, ??the second largest city in Spain, the rapid population growth had made it unbearable for the narrow streets and backward urban sanitation system of this ancient city formed in the Middle Ages. On the other hand, Barcelona has not only been an important trading city in Spain since the Middle Ages, but also the capital of Catalonia, a culturally independent and economically developed region. The sense of cultural autonomy is especially strong in a place where Catalan, not Spanish, is the first language. Since the 18th century, the Bourbon dynasty has canceled Catalonia's autonomy and even banned Catalan as the official language. Catalan culture has been severely suppressed, and both the people and the government hope that through the construction of the city To gain confidence and hope for development. The walls of the old city were demolished this year, and urban expansion and renewal were inevitable.