In the area of free movement of persons (as opposed to businesses), the EU institutions have from the Community’s inception attempted to build a social Europe. This is indeed true for the European Court of Justice which did stretch to its maximum the personal and material scope of the principle of equal treatment and the free movement provisions. A certain mutualisation of risks or social solidarity between Member States and their citizens was therefore built in the Community at its very start, and was further developed by the Court. Social solidarity was reinforced by the introduction of Union citizenship with the Maastricht Treaty and the legal force that the Court subsequently enshrined it with. Sala, Grzelczyk, Bidar, Baumbast and Collins are all cases which each in their way tell the successful story of social solidarity between the Member States and the protection of the individual rights of the Union citizens. Yet, how successful is this success story in normative and practical terms? What kind and degree of financial solidarity or mutualisation of costs does it actually underpin? The present paper will reflect on these issues looking essentially at the Court’s case-law while also pointing to the future challenges and developments of a Union based upon solidarity among its Member States and citizens.