  The formation of quasar black holes during the hydrodynamic collapse of
protogalactic gas clouds is discussed. The dissipational collapse and long-
term dynamical evolution of these systems is analysed using three-dimensional
numerical simulations. The calculations focus on the final collapse stages of
the inner baryonic component and therefore ignore the presence of dark matter.
Two types of initial conditions are considered: uniformly rotating spherical
clouds, and irrotational ellipsoidal clouds. In both cases the clouds are
initially cold, homogeneous, and not far from rotational support ($T/|W|
\approx 0.1$). Although the details of the dynamical evolution depend
sensitively on the initial conditions, the qualitative features of the final
configurations do not. Most of the gas is found to fragment into small dense
clumps, that eventually make up a spheroidal component resembling a galactic
bulge. About 5\% of the initial mass remains in the form of a smooth disk of
gas supported by rotation in the gravitational potential well of the outer
spheroid. If a central seed black hole of mass $\gsim10^6M_\odot$ forms, it can
grow by steady accretion from the disk and reach a typical quasar black hole
mass $\sim10^8M_\odot$ in less than $5\times 10^8\,$yr. In the absence of a
sufficiently massive seed, dynamical instabilities in a strongly self-
gravitating inner region of the disk will inhibit steady accretion of gas and
may prevent the immediate formation of a quasar.
