Temporary Protection, or in short – TP: an internationally non-legalized and nonconceptualized form of protection of forced migrants that since World War II has received ever growing attention. The following thesis examines the mystery’ through theory and practice. First, international protection theory is revisited and considered alongside with TP as defined in this research. Then, the core characteristics of TP are looked at in a historical context of international protection, and roots are traced back to cultural, philosophical and religious traditions, as well as to international legal sources. To bolster the derived conclusions, State and UNHCR TP-practice is examined closely, in particular to exemplify that TP is not what some believe it or might want it to be. The thesis argues that TP describes the form of international protection that is necessary if sovereign states are to be held accountable for some of their most fundamental proclamations forming part of their legitimacy. TP should be the minimum protection provided before identifying any further resolution, e.g. asylum in the form of the 1951 Convention, complementary forms of protection, or other longer-term oriented forms of protection. It is argued that in its current state, the international protection system calls for a renewed global commitment to TP, possibly to be expressed in international legal terms and supported by an organizational structure. However, in this thesis TP is not understood as threatening the existing system of international protection; it is seen instead as delineating it, or even completing it. Crucially, it has the potential to provide international protection for all those who need it, to reinforce commitment to human rights and to heal the fractured international protection system of forced migrants, which is a basis for the development of a more effective system of international migration management.