This chapter analyses the reasons why governments rejected a formal recognition of the ASEAN Interparliamentary Organization/Assembly for a long time, but finally established an official affiliation during the Charter-making process in 2008/10. Until today, ASEAN provides a comparatively unfavourable context for parliamentarization because the organization has little authority and the membership is largely non-democratic. Yet, when the Asian financial crisis hit the region in 1997/98, a demand for re-legitimation emerged, which was supplied as a result of the combination of a subsequent change in the purpose of the organization, which created affinities with other ‘parliamentarized’ organizations and diffusion from the European Union.