OverviewIn these lectures I review the deconfining phase transition in a "pure" SU (N ) gauge theory, without dynamical quarks. Gauge theories are ubiquitous in physics, so their phase transitions are manifestly of fundamental importance. Two examples may include the collisions of large nuclei at high energy and the early universe.The phase transitions of gauge theories without quarks are of especial interest, since then the order parameter, and many other aspects of the phase transition, can be characterized precisely [1,2,3]. While of course QCD includes quarks, this is not an academic exercise. Recent results from the Lattice on "flavor independence" -for both the pressure [4,5] and quark susceptibilities [6] -suggest that the results from the pure glue theory may be, in a surprising and unexpected fashion, relevant for QCD. (Whether flavor independence can be generalized when there are many light flavors is not known.)Albeit indirectly, the Lattice has already told us much about what happens in a pure gauge theory with three colors. By asymptotic freedom, at infinite 1