The exploration of the development of the gender mainstreaming strategy and its effect on, European legislation concerning gender equality, from its beginnings to today is the aim of this chapter.The focus is on the role of the European Union in promoting substantive equality for men and women improving legislation in the European Union context and favouring a cultural change in the gender equality perspective. Gender mainstreaming is analysed as the main legislative and cultural shift done for promoting gender equality in all European policies. Gender mainstreaming legislation requires the adoption of a gender perspective by all the central actors in the policy process and, even considering its limits and blunders, and is still the most crucial transnational strategy currently in existence that promotes gender equality in all domains of social life. The legislation enquiries raised at the beginning of the gender mainstreaming implementation process in the EU around 1996 focused on ...