Black holes embody one of the few, simple, solutions to the Einstein

field equations that describe our modern understanding of

gravitation. In isolation they are small, dark, and elusive. However,

when a gas cloud or star wanders too close, they light up our universe

in a way no other cosmic object can. The processes of

magnetohydrodynamics which describe the accretion inflow and outflows

of plasma around black holes are highly coupled and nonlinear and so

require numerical experiments for elucidation. These processes are at

the heart of astrophysics since black holes, once they somehow reach

super-massive status, influence the evolution of the largest

structures in the universe. It has been my goal, with the body of work

comprising this thesis, to explore the ways in which the influence of

black holes on their surroundings differs from the predictions of

standard accretion models. I have especially focused on how

magnetization of the greater black hole environment can impact

accretion systems.