  The Hill vortex is a three-dimensional vortex structure solution of the Euler
equations. For small amplitude axisymmetric disturbances on the external
surface from the linear stability analysis by \citet{moff78} emerged the
formation of a tail. Successive studies confirmed this fact, and in addition
observed a different shape of the tail with azimuthal small amplitude
disturbances. In this paper the Navier-Stokes equations are solved at high
values of the Reynolds number imposing large amplitude axisymmetric and
three-dimensional disturbances on the surface of the vortex. The conclusion is
that the azimuthal disturbances produce a hierarchy of structures inside the
vortex maintaining the shape of the vortex. On the other hand the axisymmetric
disturbances are convected in the rear side, are dumped and form an
axisymmetric wave longer higher the magnitude of the surface disturbance.
Simulations in a moving frame allow to extend the evolution in time leading to
the conclusion that the Hill vortex is unstable and produces a wide range of
energy containing scales characteristic of three-dimensional flows.
