Traumatic brain injury (TBI) is a life-threatening injury, affecting approximately 69 million people worldwide annually. TBI is characterised as an acute physical injury to brain tissue, and is typically inflicted by external mechanical force which results in a diminished or altered state of consciousness, often leading to subsequent neurological impairment. Damage to the axonal white matter tracts within the brain is a key cause of neurological impairment and long-term disability following TBI. This diffuse axonal injury (DAI) presents across the spectrum of mild, moderate and severe TBI and increases relative to injury severity. To date, most pre-clinical studies investigating DAI following TBI have been limited to the use of lissencephalic species which respond differently to traumatic shear injury than the gyrencephalic brain of humans due to structural and neuroanatomical differences. The human brain presents a higher ratio of white matter (60%) and more intricate cortical structure compared to the rodent brain (10%), which is of particular relevance given evidence that DAI develops predominantly in the white matter of the brain. Additionally, DAI pathology is largely influenced by the mechanical forces of injury. For these reasons, translation of therapies from rodent to human have been largely unsuccessful. Therefore, an intermediary species which more closely represents the human brain is required to better understand DAI pathology. As such, the aim of this research was to optimise an ovine model of moderate TBI with the absence of skull fracture in order to characterise DAI and associated pathologies following injury. These studies also explored the effects of post-traumatic hypoxia (PTH) on the development of DAI. Additionally, studies within this thesis investigated the relationship between angular and linear head acceleration following impact on the development of DAI. Finally, this thesis determined the centre of mass of the sheep head in order to develop an anatomical coordinate system (ACS) which would allow more representative calculation of head acceleration specific to the anatomy of the sheep. This will better inform the understanding of DAI pathology and development following impact in the sheep. Despite extensive troubleshooting, these findings presented suggest this model of TBI with the addition of PTH to be insufficient to effectively produce marked DAI in the absence of significant skull fracture and gross pathological lesions within the sheep. Additional modelling is required in order to reduce the incidence of skull fracture and increase the inertial force transmitted to the brain parenchyma which will encourage the production of DAI and additional microscopic TBI pathologies