Coins of the pound sterling itself was unchanged by decimalisation.) The first decimal coins – the five pence (5p) and ten pence (10p) — were introduced in 1968 in the run-up to decimalisation in order to familiarise the public with the new system. These initially circulated alongside the pre-decimal coinage and had the same size and value as the existing one shilling and two shilling coins respectively. The fifty pence (50p) coin followed in 1969, replacing the old ten shilling note. The remaining decimal coins – at the time, the half penny (p), penny (1p) and two pence (2p) — were issued in 1971 at
Penny (Irish pre-decimal coin) Penny (Irish pre-decimal coin) The penny (1d) () coin was the third smallest denomination of the pre-decimal Irish pound, worth of a pound or of a shilling. To express an amount, penny was abbreviated to "d", e.g. 1d, from the Roman "denarius". It was introduced in 1928 to replace its British counterpart, used when all of Ireland was a constituent country of the United Kingdom. The last year of minting was 1968 and it ceased to be legal tender on 31 December 1971. The coin measured in diameter and weighed 9.45 grams. The bronze coin was made up of 95.5%