Provenance, or records of the origin, context, custody, derivation or other historical information about a (digital) object, has recently become an important research topic in a number of areas, particularly databases. However, there has been little interaction between researchers across subdisciplines of computer science working on related problems. This article reports on a workshop on Principles of Provenance held in Edinburgh,Scotland in November 2007, which facilitated interaction among researchers working on provenance in databases, security, information retrieval, Semantic Web, and software engineering settings, as well as developers and database administrators who are currently working with provenance in practice, or foresee the need to do so in the near future.