A data processing system incorporates an instruction prefetch unit 8 including a static branch predictor 12. A static branch prediction cache 30, 32, 34 is provided for storing a most recently encountered static branch prediction such that a subsequent request to fetch the already encountered branch instruction can be identified before the opcode for that branch instruction is returned. The cached static branch prediction can thus redirect the prefetching to the branch target address sooner than the static predictor 12.