From Strangeness Enhancement to Quark-Gluon Plasma Discovery

This is a short survey of signatures and characteristics of the quark-gluon plasma in the light of experimental results that have been obtained over the past three decades. In particular, we present an in-depth discussion of the strangeness observable, including a chronology of the experimental effort to detect QGP at CERN-SPS, BNL-RHIC, and CERN-LHC.