  The quest for the Higgs boson of the Standard Model, which was a cornerstone
in the physics programme at particle colliders operating at the energy frontier
for several decades, is the subject of this review. After reviewing the
formulation of electroweak symmetry breaking via the Higgs mechanism within the
Standard Model, the phenomenology of the Higgs boson at colliders and the
theoretical and phenomenological constraints on the Standard Model Higgs sector
are discussed. General remarks on experimental searches and the methodology of
statistical interpretation are followed by a description of the phenomenology
of Higgs-boson production and the corresponding precise predictions. The
strategies of the experimental searches and their findings are discussed for
the Large Electron Positron Collider (LEP) at CERN, the proton-antiproton
collider Tevatron at Fermilab, and the proton-proton Large Hadron Collider
(LHC) at CERN. The article concludes with the description of the observation of
a Higgs-like boson at the LHC.
