The taxonomy and number of Cercopithecus monkey radiation events in southern Africa are still debated. To date, genetic studies have largely been limited to single specimens per taxon and a scattered geographical distribution. A recent study focusing on South African Cercopithecus monkeys showed that populations can be divided into three distinct genetic entities. Our current study aims to add new mtDNA and microsatellite data from a coastal population (Vamizi Island) in Mozambique to compare to existing data from South Africa. Our additional data allowed analysis of the number and timing of radiation events of Cercopithecus monkeys in southern Africa. Here we propose the occurrence of a single, north-south radiation event during the mid-Pleistocene along the Afromontane forest belt and that after the Last Glacial Maximum, samango populations reradiated into (re)established coastal forests on a more local scale. Our population genetic data support this pattern for both Mozambican, as well as South African samango monkey populations. By including mtDNA sequence data from Cercopithecus across Africa, we also discuss the hypothesis that the ‘Kingdon Line’ may explain the divergence of two major species in Africa within the C. mitis/nictitans group: C. albogularis and C. mitis.