Gender equality is an increasingly topical issue, but it has deep historical roots. The principle of gender equality found its legitimacy, even if limited to salary, in the 1957 Treaty of Rome, establishing the European Economic Community (EEC). This treaty, in Article 119, sanctioned the principle of equal pay between male and female workers. The EEC continued to protect women’s rights in the 1970s through equal opportunity policies. These policies referred, first, to the principle of equal treatment between men and women regarding education, access to work, professional promotion, and working conditions (Directive 75/117/EEC); second, to the principle of equal pay for male and female workers (Directive 76/207/EEC); and finally, enshrined the principle of equal treatment between men and women in matters of social security (Directive 79/7/EEC). Since the 1980s, several positive action programmes have been developed to support the role of women in European society. Between 1982 and 2000, four multiyear action programmes were implemented for equal opportunities. The first action programme (1982–1985) called on the Member States, through recommendations and resolutions by the Commission, to disseminate greater knowledge of the types of careers available to women, encourage the presence of women in decision-making areas, and take measures to reconcile family and working life. The second action programme (1986–1990) proposed interventions related to the employment of women in activities related to new technologies and interventions in favour of the equal distribution of professional, family, and social responsibilities (Sarcina, 2010). The third action programme (1991–1995) provided an improvement in the condition of women in society by raising public awareness of gender equality, the image of women in mass media, and the participation of women in the decision-making process at all levels in all areas of society. The fourth action programme (1996–2000) strengthened the existing regulatory framework and focused on the principle of gender mainstreaming, a strategy that involves bringing the gender dimension into all community policies, which requires all actors in the political process to adopt a gender perspective. The strategy of gender mainstreaming has several benefits: it places women and men at the heart of policies, involves both sexes in the policymaking process, leads to better governance, makes gender equality issues visible in mainstream society, and, finally, considers the diversity among women and men. Among the relevant interventions of the 1990s, it is necessary to recall the Treaty of Maastricht (1992) which guaranteed the protection of women in the Agreement on Social Policy signed by all Member States (except for Great Britain), and the Treaty of Amsterdam (1997), which formally recognised gender mainstreaming. The Treaty of Amsterdam includes gender equality among the objectives of the European Union (Article 2) and equal opportunity policies among the activities of the European Commission (Article 3). Article 13 introduces the principle of non-discrimination based on gender, race, ethnicity, religion, or handicaps. Finally, Article 141 amends Article 119 of the EEC on equal treatment between men and women in the workplace. The Charter of Fundamental Rights of the Nice Union of 2000 reaffirms the prohibition of ‘any discrimination based on any ground such as sex’ (Art. 21.1). The Charter of Fundamental Rights of the European Union also recognises, in Article 23, the principle of equality between women and men in all areas, including employment, work, and pay. Another important intervention of the 2000s is the Lisbon strategy, also known as the Lisbon Agenda or Lisbon Process. It is a reform programme approved in Lisbon by the heads of state and governments of the member countries of the EU. The goal of the Lisbon strategy was to make the EU the most competitive and dynamic knowledge-based economy by 2010. To achieve this goal, the strategy defines fields in which action is needed, including equal opportunities for female work. Another treaty that must be mentioned is that of Lisbon in 2009, thanks to which previous treaties, specifically the Treaty of Maastricht and the Treaty of Rome, were amended and brought together in a single document: the Treaty on European Union (TEU) and the Treaty on the Functioning of the European Union (TFEU). Thanks to the Lisbon Treaty, the Charter of Fundamental Rights has assumed a legally binding character (Article 6, paragraph 1 of the TEU) both for European institutions and for Member States when implementing EU law. The Treaty of Lisbon affirms the principle of equality between men and women several times in the text and places it among the values and objectives of the union (Articles 2 and 3 of the TEU). Furthermore, the Treaty, in Art. 8 of the TFEU, states that the Union’s actions are aimed at eliminating inequalities, as well as promoting equality between men and women, while Article 10 of the TFEU provides that the Union aims to ‘combat discrimination based on sex, racial or ethnic origin, religion or belief, disability, age, or sexual orientation’. Concerning the principle of gender equality in the workplace, the Treaty, in Article 153 of the TFEU, asserts that the Union pursues the objective of equality between men and women regarding labour market opportunities and treatment at work. On the other hand, Article 157 of the TFEU confirms the principle of equal pay for male and female workers ‘for equal work or work of equal value’. On these issues, through ordinary procedures, the European Parliament and the Council may adopt appropriate measures aimed at defending the principle of equal opportunities and equal treatment for men and women. The Lisbon Treaty also includes provisions relating to the fight against trafficking in human beings, particularly women...