The article highlights the right to liberty and security of the person. The first part of the article will discuss this human right as it exists in article 5 of the European Convention on Human Rights (the convention) and according to the interpretation of the European court of human rights (the European court). It explores the scope of application and the extent of the guarantee. The summaries of court cases in which a person has been detained will illustrate the limitations and interpretations of the right to liberty and security by highlighting the requirements and limits of lawful detention versus the right of a person to his/her liberty and security. As article 5 of the convention is not an absolute right, the second and the third part of this contribution try to assess whether the exceptions can be rationalised in a more general fashion. These are qualifications set out in article 5(1)a-f of the convention, and the possibility of derogation under article 15 of the convention. The article tries to find a way to solve the conflict between security and human rights in cases where public safety and national security are at stake.