Hexagonal close packed (HCP) alloys have a wide range of industrial uses, including within the nuclear industry and for aerospace applications.The properties of HCP alloys are highly dependent on the microstructure that develops during processing, such as texture, grain size, and defect structures. However, because current thermomechanical processing routes are not well optimised there are considerable potential improvements in performance to be made. This work will combine crystal plasticity modelling with novel characterisation methods to understand the deformation of magnesium and zirconium alloys. The shape and position of the diffractionpeaks, alongside the modelling, will allow us to determine details of the deformed microstructure not possible by other approaches. The work will also help us to develop more realistic peak profile analytical approaches.