This thesis examines the relevance of animal symbolism for group cohesion within Vendel- and Viking Age warrior groups. Late Iron Age Scandinavia (c. 550-1050) saw increased political centralization where leading figures would legitimize and maintain their authority by forming and maintaining warrior groups. Animal symbolism is examined with regards to its role in stimulating processes of 'ingroup identification and identity fusion, which are likely to have been of vital importance in facilitating cohesion within ancient Scandinavian warrior groups. Literary, historical and archaeological sources are examined and compared in order to identify independently reoccuring phenomena, which collectively provide indications about the martial ideologies and practices of the Vendel- and Viking periods. Animals were used as identifying symbols for specific individuals, groups and organizations which could hade served to identify group members and hightlight the distinctiveness of ingroups in order to stimulate cooperation. Particular animals such as ravens were used by Scandinavian leaders in order to indicate martial competency and connections to the god Odin. Both of these functions would have increades the warrior bands' confidence in, and presumably loyalty towards their commanders. Animal symbolism was likely used by some warrior groups in the assumption of therianthropic identities. Conceptions of therianthropy could have stimulated identity fusion by cultivating specific personality traits, providing ideological motivations for violent actions, enhancing actual or perceived combat performance and by distinguishing therianthropic warriors from the rest of society. The relevant forms of animal symbolism would have coexisted to various degrees withing the same or similar ideological frameworks with Odin as a reoccuring and significant - but not necessarily essential - central figure.