Europe is not as calm as one might think. There are currently several secessionist struggles that are ongoing in the region and in this thesis three of them will be researched. This thesis has investigated the biggest democratically elected actor that wants secession in Flanders, Catalonia and Scotland. This has been done by questioning how they argue for their secession and how these arguments relate to different approaches to legitimize secession. These approaches being the remedial approach, the free choice approach, the functional approach, the exit approach and the anti-theory approach. This was performed by using a qualitative content analysis. With this method I created an analytical scheme which was applied to the arguments in order to sort them into the scheme. The arguments used by the actors were pluralistic, relating to democracy, nationalism, administration, governance, economy, grievance and history. This proved that the actors are much more pluralistic than what theory could handle hence, none of the actors fit to either one of the approaches as they argued in a multitude of different ways. In addition to this, I was also able to show that against theoretical assumptions these secessionist actors didn’t favour external legitimacy. Even though this is argued by some to be most important for secessionist groups to gain independence. In the end the implications of this thesis are that secessionist actors are incredibly pluralistic, and it is quite hard for theory to fully capture this plurality. Hence, secessionist theory gives a very incomplete picture of how secessionist actors try to legitimize their secession.