The Irish Pound (Irish: Punt Éireannach) was the currency of Ireland until 2002. Its ISO 4217 code was IEP, and the usual notation was the prefix £ (or IR£ where confusion might have arisen with the pound sterling or other pounds). The Irish pound was superseded by the euro on 1 January 1999. Euro currency did not begin circulation until the beginning of 2002.

The earliest Irish coinage was introduced in the year 997, with a pound divided like the English pound into twenty shillings, each of twelve silver pence. Parity with the pound sterling was established by King John around 1210, so that Irish silver could move freely into the English economy and help to finance his wars in France. However, from 1460, Irish coins were minted with a different silver content to those of England, so that the values of the two currencies diverged.

During the Williamite War of 1689–1691, King James II, no longer reigning in England and Scotland, issued an emergency base-metal coinage known as gun money.

In 1701, the relationship between the Irish pound and the English pound sterling was fixed at thirteen Irish pounds equalling twelve English pounds. (The Scottish pound had yet another value.) This relationship made it possible for Irish copper coins to circulate with English silver coins, since thirteen Irish pence had the same value as one English shilling.

In 1801, Ireland became part of the United Kingdom of Great Britain and Ireland, but the Irish pound continued to exist until January 1826. Between 1804 and 1813 silver tokens worth tenpence were issued by the Bank of Ireland and were denominated in pence Irish. The last copper coins of the Irish pound were minted in 1823, and in 1826 the Irish pound was merged with the pound sterling. After 1826 some Irish banks continued to issue paper bank notes, but these were denominated in pounds sterling, and no more distinctly Irish coins were minted until the creation of the Irish Free State in the 20th century.

...
Wikipedia