Quantum Electrodynamics in Strong Laser Fields Within the next few years progress in laser technology will lead to the realisation of unprecedented extremes in laser power (> 1016 W), intensity (> 1023 W/cm2) and, accordingly, electric field strength (> 1015 V/m). In this regime charged probes experience relativistic dynamics, and quantum (vacuum) effects come within reach. Hence, the appropriate theoretical tool is a relativistic quantum field theory, namely strong-field quantum electrodynamics (QED). This describes the interaction of leptons and photons with an extreme classical background field provided by the laser. In my talk I will give an overview over the planned facilities and provide an outline of the fundamental particle physics experiments envisaged there. Examples will include high-intensity Compton scattering, laser induced "vacuum breakdown" (via pair production), light-by-light scattering of real photons and vacuum birefringence.