There is provided a system havingan execution core operable to execute internal instructions.A translation buffer is operable to store a plurality of internal instruction blocks of one or more internal instructions where the internal instruction blocks are a dynamic translation of respective external instruction blocks of one or more external instructions.A remapper is responsive to an execution request for an external instruction that is within one of said external instruction blocks to identify a corresponding internal instruction block stored within said translation buffer. Thus one or more internal instructions from said corresponding internal instruction block can be supplied to execution core.