Interested in transnational approaches, his main lines of research are cultural history of politics and comparative history of Spain and Latin America. Currently, he works on the history of utopias.

He is currently the coordinator of the Transatlantic Network of Utopian Studies [Red Trasatlántica de Estudio de las Utopías]] and the director of HISTOPIA Research Group.

He is the author of 9 books, 33 journal articles, 56 chapters in collaborative books, and 160 papers in conferences and scientific meetings; and he has edited 6 collaborative books and 6 special issues in academic journals. He has participated in 21 research projects (from European, national and regional competitive calls) and he has directed 5 of them.

His book, "La construcción del Estado en España: una historia del siglo XIX" (Madrid: Alianza Editorial, 2019) [State building in Spain: A History of the Nineteenth Century], a synthesis and a revaluation of his works during thirty years, is probably his most important publication, and has had a considerable impact.

Membership of the Board of Directors of the Contemporary History Association, Spain, (2006–2014), Secretary (2006–2010) and Vice President (2012–2014).

Member of the Editorial Board of the JCR academic journal Ayer: Revista de Historia Contemporánea between 2006 and 2014, and also Secretary (2010–2012) and Director (2012–2014).

Coordinator of the inter-university Master’s degree (2011–2014) and Doctorate programme in Modern and Contemporary History (2011–2020), Universidad Autónoma de Madrid.

Member of 3 award juries; 7 project and grant evaluation committees in Spain, France and Portugal; referee of articles for 15 journals in Spain, France and Argentina; member of editorial board of 4 academic journals.

He has supervised 11 doctoral theses and his still supervising 3 more.