Horse-depositions were examined to explore the development of human-horse relationships in early Britain using a multidisciplinary approach (osteological, archaeological, historical and ethnographical) to interpret these relationships as part of Horseman identities in the Iron Age, Roman and medieval periods. Medieval Horseman-burials are an established phenomenon and considered an Anglo-Saxon import in Britain which expressed a general elite-warrior male status. However, Horseman-burials form an exclusive minority which suggest not a general warrior elite but specific subgroups and/or traditions potentially rooted in earlier practices. Husbandry, transportation-use and ritual practices were also investigated. Horses and horse-use were evaluated via stature and correlations with sex. The results indicated sexual dimorphism should be considered when interpreting horse stature. It is hypothesised that generally females were pastured breeding-stock while males were transportation-stock which received supplemental nutrition and care. Males were/are generally larger than females, and size disparity was probably heightened by such gendered horse-use practices. Overall, it appears females were 1.3m or less, and horses over 1.3m were males. Horse-depositional patterns in human, particularly funerary, spaces were analysed. Horse deposition often had ritual components and practices changed over time reflecting changing Horseman identities, particularly during the Roman period. Roman-British interactions, the destruction of native-elite chariot-warfare identities and the development of native-auxiliary groups refocused Horseman identities on mounted-warfare. This change from driver to rider, a more intimate relationship, appears reflected by the development of human-horse burials and Horseman identities linked to auxiliary-native cultural groups which incorporated Roman equites ideals with native-auxiliary and imported Eurasian Horseman traditions. / Arts & Humanities Research Council (AHRC). Financial support also came from the project partners, particularly author Bernard Cornwell, the Sutton Hoo Society. Additional financial support for equine osteological research was supplied by SYNTHESYS. / The appendices which accompany the thesis are not available online.