 To participate in the ERM, Ireland had to break the Irish pound's parity with the pound sterling in 1979, because the pound sterling, which was not an ERM currency, appreciated against all ERM currencies shortly after the launch of the ERM.The continued parity between the Irish pound and the pound sterling would have taken the Irish pound outside its agreed band.To fulfill the ERM conditions, the Irish government was required to break the parity of the Irish pound with the pound sterling.