This chapter examines the development of regulatory frameworks for two key areas in Spain, spanning from the 1980s to the latest EU initiatives. Initially, we provide an overview of the regulatory landscape for telecommunications and contrast its primary features with those of the newly introduced Digital Markets Act (DMA). Next, we trace the evolution of regulatory measures targeting information society services, beginning with an analysis of the e-commerce directive (ECD) and its implementation in Spain, followed by an examination of the Digital Services Act (DSA) and its potential implications for Spanish regulation. As the current regulatory framework is still in its early stages, we investigate the potential influence of case law on shaping the trajectory of these new regulations, drawing on historical precedents that have significantly impacted the development of previous regulatory frameworks. Furthermore, we investigate the institutions established to oversee these regulations, outlining the evolution of the organizational structure and discussing unresolved issues related to their effectiveness. Finally, we compare the initial approaches to regulating telecommunications and information society services with the recent EU initiatives, highlighting a significant paradigm shift towards a more proactive and interventionist approach, characterized by a move away from minimal, ex-post intervention and towards a more comprehensive and forward-looking regulatory strategy. We contend that as the digital transformation increasingly defines the economic, social, and political contours of the European Union, the regulatory approach has assumed greater importance and breadth, extending beyond traditional digital ecosystem domains.