The fundamental mechanisms controlling hot deformation texture formation in aluminium alloys are characterised by high temperature (350-550 degrees) channel-die compression tests on Al-1%Mn crystals at strain rates up to 10 s(-1). It is shown that, depending on the orientation, non-octahedral slip can be activated, usually in association with classical octahedral slip. The particular problem of the stability of cube grains in PSC is addressed in detail. The hgh temperature, high strain flow stresses of the different families of slip systems are evaluated over 5 decades of strain rate. These flow stresses are used to model hot deformation textures in Al alloys for simple strain paths such as tension, compression and plane strain compression. The good agreement with experimental textures provides a basis for extending the model to complex strain paths encountered in industrial practice. Using Finite Element data as input, the textures and their through-thickness gradients are simulated for hot extrusion and hot reversible and tandem rolling of commercial alloys.