We begin with Robert Ladrech's definition of Europeanization, viz. 'a process by which individuals and organizational actors and institutions respond to the altered condition of their operating environment due to the changes wrought by the development of the European Union' (2000). This definition stresses the adaptive response of organizations. Ladrech suggests several axes along which one might measure party response or, if one prefers, the degree of parties' Europeanization. Programmatic change is the most visible, followed by organizational change. Ladrech also highlights possible changes to the nature of party competition or party--government relationships and, lastly, changes to relations beyond national party systems. Some of these categories are very broad, and one cannot treat them all in a single article; nor can one take a bottom-up approach focusing on all the individual Christian Democratic (CD) parties in order to assess their degree of Europeanization, for obvious reasons of space.