The Himalayas support a highly rich, diverse, multi-layered, mostly endemic diplopod fauna which presently contains >270 species, 53 genera, 23 families and 13 orders. This is the result of mixing the ancient, apparently Tertiary and younger, Plio-Pleistocene elements of various origins, as well as the most recent anthropochore (= man-mediated) introductions. At the species and, partly, generic levels, the fauna is largely autochthonous and sylvicolous, formed through abounding in situ radiation and vicariance events. In general, the species from large genera and families tend to occupy a wide range of altitudes, but nearly each of the constituent species shows a distribution highly localized both horizontally and altitudinally, yet quite often with sympatry or even syntopy involved. The bulk of the fauna is Indo-Malayan in origin, with individual genera or families shared with those of SE Asia (mostly) and/or S India (few). Sino-Himalayan and, especially, Palaearctic components are subordinate, but also clearly distinguishable.