  Let $S$ be the left $R$-bialgebroid of a depth two extension with centralizer
$R$ as defined in math.QA/0108067. We show that the left endomorphism ring of
depth two extension, not necessarily balanced, is a left $S$-Galois extension
of $A^{\rm op}$. Looking to examples of depth two, we establish that a Hopf
subalgebra is normal if and only if it is a Hopf-Galois extension. We find a
class of examples of the alternative Hopf algebroids in math.QA/0302325. We
also characterize finite weak Hopf-Galois extensions using an alternate Galois
canonical mapping with several corollaries: that these are depth two and that
surjectivity of the Galois mapping implies its bijectivity.
