John O' Brennan acted as one of two moderators (along with Prof. John Fitzgerald of the ESRI) at a conference marking ten years of the European Union's largest accession at Dublin Castle.
Other speakers at the conference which reflected on the significance of the accessions to the EU by countries from Central and Eastern Europe in 2004 included academic and diplomats from the Czech Republic, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia.
Irish participants included the Minister for European Affairs, Paschal Donohoe TD, Barbara Nolan of the European Commission representation in Ireland and Francis Jacobs of the European Parliament Office in Dublin.
The website for the conference can be accessed here: http://www.europarl.ie/en/at_your_service/events_activities/events_and_activities_2014/enlargement.eu/portal/en/legal-notice