  We investigate the emergence of anti-ferromagnetic ordering and its effect on
the helical edge states in a quantum spin Hall insulator, in the presence of
strong Coulomb interaction. Using dynamical mean-field theory, we show that the
breakdown of lattice translational symmetry favours the formation of magnetic
ordering with non-trivial spatial modulation. The onset of a non-uniform
magnetization enables the coexistence of spin-ordered and topologically
non-trivial states. An unambiguous signature of the persistence of the
topological bulk property is the survival of bona fide edge states. We show
that the penetration of the magnetic order is accompanied by the progressive
reconstruction of gapless states in sub-peripherals layers, redefining the
actual topological boundary within the system.
