The Department of Architecture and Planning was formed in 2001 when colleagues from other research sites of the Polytechnic were merged into the Department of Territorial Sciences. The name change reflected the new composition, characterised by the presence of numerous new disciplinary areas, important for a multidisciplinary research approach, which no longer involved just urban design, urban planning and social sciences, but also architectural design and urban history, restoration and representation. Territorio, a Dst journal founded by Cesare Macchi Cassia in 1987 and edited by him until 1994, changed its format and programme to represent the new department, the second largest in the Polytechnic by number of teaching staff and perhaps the largest in terms of its broad disciplinary scope. In the years that followed Territorio became a forum where different approaches and areas of expertise met and in a plurality of forms and ways it has made a substantial mark, influencing the trajectories of both individuals and groups of researchers. The profound changes in progress, due to the massive generation turnover, forced in part by ministerial measures, led to the publication of this special edition, with articles by 32 colleagues who are retiring in 2007 or will leave the university by 2011. It seemed the most direct and useful way to underline the work of the Diap and to document it in the words of some of its members. Most of the papers have already appeared in the journal and in other cases the authors were given the option of proposing papers published elsewhere in order to fill out different subject areas. A ‘light’ platform was chosen, grouping contributions under four general sets of key words, the same which appear as the factors which characterise Diap research on the new website of the department: Design-City, Landscape-Environment-Development, Governance-Mobility-Times, Living-Territory-Society. They are broad sets if considered alone, but they become significant if placed together within the same academic environment. While we are aware of the difficulties which have not always made profitable agreement possible, we nevertheless feel that a reading of this edition of Territorio may stimulate thought both within and outside the department, above all because it identifies many promising points of unification which could open up interesting developments for research. We wish to thank all our colleagues who willingly participated in the initiative, many with enthusiasm, and also the editorial staff who with their usual care were quick to make it possible.