  We derive inflation from M-theory on S^1/Z_2 via the non-perturbative
dynamics of N M5-branes. The open membrane instanton interactions between the
M5-branes give rise to exponential potentials which are too steep for inflation
individually but lead to inflation when combined together. The resulting type
of inflation, known as assisted inflation, facilitates considerably the
requirement of having all moduli, except the inflaton, stabilized at the
beginning of inflation. During inflation the distances between the M5-branes,
which correspond to the inflatons, grow until they reach the size of the
S^1/Z_2 orbifold. At this stage the M5-branes will reheat the universe by
dissolving into the boundaries through small instanton transitions. Further
flux and non-perturbative contributions become important at this late stage,
bringing inflation to an end and stabilizing the moduli. We find that with
moderate values for N, one obtains both a sufficient amount of e-foldings and
the right size for the spectral index.
