In recent years the JET scientific programme has focussed on addressing physics issues essential for the consolidation of design choices and the efficient exploitation of ITER in parallel to qualifying ITER operating scenarios and developing advanced control tools. Active methods have been developed to mitigate, without adversely affecting confinement, Edge Localised Modes (ELMs) along with a systematic characterisation of the edge plasma, pedestal energy and ELMs, and their impact on plasma facing components as well as their compatibility with material limits. The unique JET capability of varying the Toroidal Field (TF) ripple from its normal low value dBT = 0.08% up to dBT = 1% has been used to elucidate the role of TF ripple on confinement and ELMs. Increased TF ripple in ELMy H-mode plasmas is found to have a detrimental effect on plasma stored energy and density, especially at low collisionality. The development of ITER advanced tokamak scenarios has been pursued. In particular, bN values above the 'no-wall limit' (bN ~ 3.0) have been sustained for a resistive time. Gas balance studies combined with shot-resolved measurements from deposition monitors and divertor spectroscopy have confirmed the strong role of fuel co-deposition with carbon in the retention mechanism through long-range migration and also provided further evidence for the important role of ELMs in the material migration process within the JET inner divertor leg.