The moment was 21 May 1998. Indonesia witnessed the demise of the New Order government led by Suharto. The end of the regime led to the emergence of myriad political parties, civil society groups and social movements of varying ideological orientation. The most visible of these were Islamist groups. One such group was HTI. This chapter seeks to understand the external factors that impacted upon the emergence and growth of HTI. It also seeks to understand the decision-making process of the party’s leadership in forming a chapter of HT in Indonesia, expanding its membership base and finally emerging publicly to launch collective actions. This chapter argues that both institutional and non-institutional opportunities affected the actions, strategy and ability of HTI in mobilizing its members in launching collective action.