The article describes institutional change in the Spanish higher education system over the past two decades. It singles out four variables in explaining this change: (i) demography, (ii) economic environment (the so-called knowledge society), (iii) the role and interests of academics and politicians, and (iv) the supranational stimulus to converge (Bologna Process). Although after Franquism each of these factors had notable consequences on tertiary education, at least initially it seems that supply-side factors were very important in sustaining institutional change in Spanish universities. Above all, politicians and regional governments boosted democratisation by opening new universities (which since 1980s have increased in number from 32 to 70), by lowering entrance requirements, and by keeping fees low. At the end of the 1990s, European declarations (Sorbonne, Bologna) increased the significance of Europe, with a twofold effect: they induced governments to introduce change in higher education systems (convergence), but they also highlighted the difficulty of combining the role of the state (as signatory to international declarations) and peripheral institutions ("Comunidades autonomas" and autonomous universities).