This title on the liability of public authorities in comparative perspective inaugurates a new series of books by the European Group of Tort Law under the name Principles of European Tort Law. The Group was established in 1992 and consists of scholars from several European countries and beyond. It aims to contribute to the enhancement and harmonisation of tort law in Europe through the framework provided by its Principles of European Tort Law (PETL), published in 2005, and its related and ongoing research, and in particular to provide a principled basis for rationalisation and innovation at national and EU level. The Group reconvened in 2009 to work on expanding the PETL's scope and updating and refining its content in the light of subsequent scholarly debates and developments in national and EU law. One part of this work programme is to publish a series of preliminary studies on topics not addressed in the initial edition of the PETL, of which public authority liability is one.

The topic of public authority liability was adopted by the Group at a meeting in Prague in October 2010, at which I was appointed project leader. The project began formally at the Group's next meeting, in Vienna in April 2011, at which we discussed my draft project description and questionnaire (including case studies). The documents were amended in light of that discussion. The issues raised by the questionnaire, and the possible drafting of principles of public authority liability, were then discussed in several subsequent meetings of the Group: in Geneva (October 2011); Vienna (April 2012); Lausanne (October 2012); Graz (April 2013); and three more times in Vienna (April 2014, April 2015 and March 2016). Public presentations were made by Group members in conjunction With the Geneva and Graz meetings.

Initial drafts of the reports contained in this volume were first submitted in 2011, then revised in the light of editorial feedback and Group discussions as the project proceeded, taking account of more recent developments where necessary.