Furthermore, in 2012 he was Visiting Professor at the Department of History of Art of the University of Pennsylvania (USA) and Fellow of the Japan Society for the Promotion of Science (JSPS) at  Nagasaki Junshin Catholic University. Recently he was a Samuel H. Kress Senior Fellow at the Center for Advanced Study in the Visual Arts  (CASVA) at the National Gallery of Washington (USA), throughout the 2017-2018 academic year.

His research is focussed fundamentally on the study of the Romanic, especially iconography as well as the Jacobean pilgrimage. He is a recognised specialist in the Cathedral of Santiago. However, in recent years he has expanded his field of study to include the topics of Medieval Mediterranean, pilgrimage to the Holy Land and contacts between the Latin and Byzantium world. Outstanding among his books are the following: El calendario medieval hispano. Textos e imágenes (siglos XI-XIV), Junta de Castilla y León, Salamanca, 1996; Introducción al método iconográfico, Ariel, Barcelona, 1998; El Pórtico de la Gloria, Madrid, 1999; A vieira en Compostela. A insignia da peregrinación xacobea, Santiago, 2007; El Románico en las colecciones del MNAC (con Jordi Camps), Lunwerg, Barcelona, 2008; El Tapiz de la Creación de Gerona (Gerona, 2011); El Camí de Peregrinació a Santiago i el culte a la Mare de Déu en el Romànic, Besalú, 2013 (digital publication: Síntesi. Quaderns dels Seminaris de Besalú, 1, 2013, pages 1-125); Pintar fa mil anys. Els colors i el ofici del pintor romànic, Bellaterra, UAB, 2014 (with Judit Verdaguer);  Galicia e os Camiños de Santiago, Xunta de Galicia, 2016; Entre la letra y el pincel: el artista medieval. Leyenda, identidad y estatus, El Ejido, Almeria, 2017; ROMANESQUE PATRONS AND PROCESSES. Design and Instrumentality in the Art and Architecture of Romanesque Europe, eds. Jordi Camps, Manuel Castiñeiras, John McNeill, Richard Plant, Routledge, New York, 2018.

He has also been a curator of important international exhibitions such as El románico y el Mediterráneo. Cataluña, Toulouse y Pisa, 1120-1180, MNAC, 2008 (in collaboration with J. Camps) and Compostela y Europa. La historia de Diego Gelmírez, organised by the Xacobeo in Paris, Rome and Santiago and accompanied by a magnificent book-catalogue published by Skira (Milan, 2010).

He is the president of the International Committee of Experts in the Camino de Santiago of the Xunta de Galicia, Overseas Representative in Spain for the British Archaeological Association, and Associé correspondant étranger de la Société Nationale des Antiquaires de France, whose centre is in the Musée du Louvre.

In recent years he was the Principal Researcher heading research projects at the MICINN Artists, Patrons and Public. Cataloni and the Mediterranean (XI-XV centuries) – MAGISTRI CATALONIAE (HAR2011-23015) y Movilidad y transferencia artística en el Mediterráneo Medieval: artistas, objetos y modelos – Magistri Mediterranei (HAR2015-6388-P) (www.magistrimediterranei.org); he is currently the lead researcher of the Consolidated Research Group of the Regional Government of Catalonia: MAGISTRI CATALONIAE – Estudis culturals de la Mediterrània Medieval (s. XI-XV) (SGR 2017-231). In this context he has been one of the organisers of the III International Romanesque Conference of the British Archaeological Association, Romanesque Art: Patrons and Processes (Museu Nacional d’Art de Catalunya, Barcelona, 7-9 April 2014) and is the Scientific Director of the I Simposi Internacional Magistri Cataloniae: Artista anònim, artista amb signatura. Identitat, estatus i rol de l’artista en l’art medieval, Universitat Autònoma de Barcelona-Museu Episcopal de Vic (7-8 November 2014).

It is currently the director of Ad Limina. Revista de Investigación del Camino de Santiago y de las Peregrinaciones.