Background and relevance The construction and ongoing integration of the European Higher Education Area (EHEA) and the European Research Area (ERA) have reshaped the European knowledge policies, i.e. the policies related to higher education, research and innovation. The emergence of a European layer beyond the nation state has added further complexity in the governance of knowledge and its multi-level endeavour (Piattoni, 2010). For some, different sets of governance chains across local, regional, national and European level have been set in motion (Moos & Wubbels, 2014). Others see the creation of a new policy space in education as an example of how the EU constructs multiple arenas to coordinate diversified actors and engage appropriate agencies and elites in relevant policies (Lawn, 2011). Other scholars have focused on the tensions emerged with the addition of a European layer in higher education, research and innovation. On the one hand, this has led to vertical tensions between actors at different governance levels (e.g. the European Commission creeping competence in the area of higher education, Trondal (2002)). On the other hand, it has also intensified already existing horizontal tensions between actors from different sectors, such as higher education, science and technology or innovation (Chou & Gornitzka, 2014). Apart from such multi-level and multi-sector challenges to coordination, the increasing involvement of non-state actors at the local, national and European levels has added further complexity to European governance of knowledge policies. Participation and influence of non-state actors in governance reflects what Piattoni calls the state-society dimension (2010), it adds a multi-actor aspect to the multi-level one (Chou, Jungblut, Ravinet, & Vukasovic, 2017) and a 'transnational flavour' to already existing supranational and intergovernmental dynamics (Elken & Vukasovic, 2014). In this context it is thus relevant and urgent to study transnational actors as particular organizational forms emerging and thriving in the European arena (Ball & Junemann, 2012; Pataki, 2015). To do this it is necessary to analyse such actors highlighting the differences and commonalities in their structures, identities, roles, as well as the links in which they are embedded, and the influence they can exert in the formation of knowledge policies.