The 48th Congress of German Historians was held in Berlin from September 28 through October 1, 2010, and had as theme "On Borders." This is the official proceedings volume of the German Association of Historians and the Association of German History Teachers. It contains abstracts of all presentations held at the congress. In over 70 sections the attendees discussed the theme of borders - the borders of national states, natural borders, and borders between eras and disciplines. Also included are the official speeches in the special events, among others, the opening speech of the German Chancellor Dr. Angela Merkel.