African mole-rats are a unique taxon of subterranean rodents that range in sociality from solitary-dwelling species through to two 'eusocial' species, the Damaraland Mole-Rat and the Naked Mole-Rat. The Naked Mole-Rat is arguably the closest that a mammal comes to behaving like social insects such as bees and termites, with large colonies and a behavioural and reproductive division of labour. As a family, the Bathyergidae represent a model system with which to study the evolution and maintenance of highly social cooperative breeding strategies. Here, Nigel Bennett and Chris Faulkes provide a synthesis of the current knowledge of bathyergid systematics, ecology, reproductive biology, behaviour and genetics. With this, they explore the role of these factors in the evolution of sociality in the Bathyergidae in the context of both vertebrates and invertebrates. This will be an important new resource for anyone interested in the evolution of sociality, and in mole-rats in particular.