The Brexit story is full of surprises, unexpected turns and disappointments. Nobody really expected that the referendum of June 23, 2016 would result in a success for the Brexiters, and that the government would execute it with such decisiveness and rigor; many argued that the government simply had to follow what “the people” had decided and forgot about the advisory nature of the referendum and the constitutional principle of the supremacy of Parliament. Surprisingly for them, the High Court and the Supreme Court very clearly confirmed the constitutional need for the government to obtain parliamentary authorisation in order to trigger Article 50 TEU, and also surprisingly clear was Parliament’s vote on this authorisation, in spite of the fact that before the referendum a strong majority of the Parliament had defended exactly the opposite point of view. That Theresa May, having an absolute majority in Parliament for her party, should decide to call new elections in order to gain support for her strategy of a hard Brexit was unexpected, and so was the clear refusal of the British people to follow her. Nothing suggests that Theresa May will remain in office for the full period of the negotiations. Given her failure in the recent elections, it came as a surprise that these negotiations finally started on June 19 2017. The only obvious certainty is that the two years provided under the Treaty for coming to an arrangement on the conditions of Britain’s withdrawal will be over by 29 March 2019. And given the enormous workload and complexity that the negotiations entail, there is little hope that this deadline will be met. Would the negotiators emerge with an agreement? Would the agreement be accepted by a qualified majority of the Council, as required by Article 50 TEU? Would it receive the consent of the European Parliament, and would Britain accept it by simple act of Parliament? Or would a new referendum be needed? Many things can change within two years, including the weight of young British voters compared to that of the elderly, whose votes were decisive in the June referendum. Many of these questions are closely related to the meaning of democracy, and if the title of the present paper offers the choice between characterising Brexit as an exercise of, or a challenge to, democracy, perhaps the only certainty is that, wherever the process may lead the Union, the outcome must be democratic. The answer to the question will consist of three parts: 1. The Brexit process is no doubt an exercise of democracy in some respect; 2. It must be understood as a challenge to democracy in some other respect; 3. And it is a process from which we can and should draw some lessons for the future. In explaining this answer, further questions of great importance, such as “What actually is democracy?”, or the question of whether 3 “democracy” is a term that can be easily applied in EU contexts, cannot be answered in depth. For a number of questions of principle, reference is made to the proceedings of the last ECLN Conference in Thessaloniki in May 2015, published under the title “Legitimacy Issues of the European Union in the Face of Crisis”. 1 This book has only just come out. In its attempt to provide an explanation for the three answers above, the present paper focuses on four questions: Are the terms provided in the EU-Treaty for withdrawal of a Member State democratic? Was the process leading to the UK government’s provision of notice of withdrawal under Article 50 TEU democratic? What are the democratic rights of the citizens directly affected by a Brexit and how are EU citizens represented in the process? And what does the Brexit process tell us about democracy in practice?