Institut de recherche sur les lois fondamentales de l'Univers

Galaxy clusters magnify the images of distant galaxies that serendipitously lie behind them.  This gives us the opportunity to spatially resolve distant galaxies in a level of detail which would otherwise require the increased light grasp and resolution of the next generation of telescopes.  In this talk, I will present some recent results which have exploited strong lensing to resolve the gas and star-formation within galaxies between z=2--5 on scales between 100pc and 1kpc, measuring the interaction between star-formation and gas dynamics  on these scales.  These results provide an exciting glimpse of the science that will be possible once ELT and ALMA reach full science operations.