  Black holes came into existence together with the universe through the
quantum process of pair creation in the inflationary era. We present the
instantons responsible for this process and calculate the pair creation rate
from the no boundary proposal for the wave function of the universe. We find
that this proposal leads to physically sensible results, which fit in with
other descriptions of pair creation, while the tunnelling proposal makes
unphysical predictions. We then describe how the pair created black holes
evolve during inflation. In the classical solution, they grow with the horizon
scale during the slow roll-down of the inflaton field; this is shown to
correspond to the flux of field energy across the horizon according to the
First Law of black hole mechanics. When quantum effects are taken into account,
however, it is found that most black holes evaporate before the end of
inflation. Finally, we consider the pair creation of magnetically charged black
holes, which cannot evaporate. In standard Einstein-Maxwell theory we find that
their number in the presently observable universe is exponentially small. We
speculate how this conclusion may change if dilatonic theories are applied.
