  We give an introduction to Heavy Quark Effective Theory (HQET). Our emphasis
is on its formulation non-perturbative in the strong coupling, including the
non-perturbative determination of the parameters in the HQET Lagrangian. In a
second part we review the present status of HQET on the lattice, largely based
on work of the ALPHA collaboration in the last few years. We finally discuss
opportunities and challenges.
