Abstract
The text starts with four preliminary issues followed by the etymological definition of the words city, urban and agglomeration. In the main part of the text the production of the concept of city is examined in original texts of selected authors, presented in six periods over the nineteenth and twentieth centuries: (1) pre-academic period (1810-1869); (2) period of institutionalization of the social sciences (1870-1923); (3) period between the world wars (1914-1944); (4) post-war period, the "glorious 30 years" (1945-1972); (5) period from the beginning of the current crisis (1973-1994); (6) current period (1995-2015). In the final considerations the question is raised about the appropriateness of referring to the word "city" for complex phenomena so diverse in different times and spaces.
Concept; City; Urban space; Periods