century that the archival discipline began flourishing and has continued since. It did so by borrowing from different fields: the debate between historians and archivists led to the affirmation of the historical method of analysis; the strong relationship with library science affected retrieval practices and theories; the first attempts to introduce mechanisation in public administration changed documentation processes; information science changed the relationship of archives with technology; social sciences questioned archival behaviour, processes, and policies; and post-modernism spurred a debate about archival identity and purposes. However, the core of archival knowledge dating back to Sumerian times has not changed, and neither has the body of concepts and principles that accrued around that core between the 16th and the 19th centuries, because the core has controlled the use of knowledge taken from other disciplines and shaped the outcome of interactions with them.