  We present a local but fully nonlinear model of the solar tachocline, using
three-dimensional direct numerical simulations. The tachocline forms naturally
as a statistically steady balance between Coriolis, pressure, buoyancy and
Lorentz forces beneath a turbulent convection zone. Uniform rotation is
maintained in the radiation zone by a primordial magnetic field, which is
confined by meridional flows in the tachocline and convection zone. Such
balanced dynamics has previously been found in idealised laminar models, but
never in fully self-consistent numerical simulations.
