The advent of improved data and models in the last few years has led to new focus on the effects of the mass spectrum and the presence of binary stars in globular clusters\refto{HutB,PhiKu}. Observations preclude the $>100\,\msun$ black holes postulated in cores of globulars\refto{Larson,Lauer}, but the realisation that medium mass primordial black holes may form in significant numbers\refto{ShriNew} promises more subtle dynamical implications. Primordial black holes will segregate to the core of globulars through dynamical friction, producing binaries and hierarchical multiples. Dynamical evolution leads to the ejection of most of the black holes and after a few relaxation times the typical cluster should contain 0--4 black holes in its core and, possibly, a few black holes in the halo. The presence of black holes in cluster cores is an additional parameter in cluster evolution. Binary, triple and quadruple black holes in cluster cores destroy main--sequence and giant binaries, and may account for anomalies in the binary distribution. In very dense clusters hierarchical black hole multiples may explain the anomalous colour gradients observed.
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