Irish pound
When the old £sd system (consisting of pounds, shillings, and pence) was in operation, the United Kingdom and Ireland operated within the Sterling area, effectively a single monetary area. The Irish pound was created as a separate currency in 1927 with distinct coins and notes, but the terms of the Irish "Currency Act" obliged the Irish currency commissioners to redeem Irish pounds on a fixed 1:1 basis, and so day-to-day banking operations continued exactly as they had been before the creation of the Irish pound. The Irish pound was decimalised on 15 February 1971, the same date as the British pound.