The Norman conquest of Ireland began in 1169, and by 1172 the Irish chiefs were forced to accept the control of Henry II. The efforts of Henry VIII to impose the Reformation of the Church on Ireland began a period of brutal repression which led to several uprisings against the British Crown. Elizabeth and, later, Cromwell put down minor rebellions, but the wars of the 1630s and early 1640s set the pattern of religious intolerance which has persisted to the present day.

Communications with Ireland prior to 1598 were irregular and depended on occasional vessels or the official ships which maintained contact between the King and Governor of Ireland. In that year a regular post was fixed via Holyhead or Bristol. Roads through Wales proved difficult and the route was changed to Chester and the River Dee by 1640.

During the English Civil War Charles I tried to move his Irish army to Britain to fight on his side, but for some time such moves were frustrated by Parliamentary control of the northern ports. By the time that the troops were transferred, the Parliamentary army had become too strong and severe defeats were inflicted. In 1649 Cromwell and Ireton invaded Ireland, massacred the garrison at Drogheda, and reduced the whole island. By then the separation of Catholics in the southern part of the island and Protestants in Ulster had already begun.

1650-1793
During this period, Ireland remained part of the British Crown, but was garrisoned by British troops. Following his abdication by flight on 11 December 1688, James II landed in Ireland on 12 March 1689. He was pursued by William of Orange, who landed at Carrickfergus on 14 June 1690. They met at the Battle of the Boyne on 1 July 1690 and James was completely defeated. The war was finally ended after the surrender of Limerick in October 1691. A period of peace followed, broken in 1760 during the Seven Years' War when a French commodore called O'Farrell or Thurst (his mother's name) invaded Carrickfergus and plundered the town. He was trapped by a British squadron and defeated on 28 February 1760.

The first post in Ireland was established at Dublin in the last quarter of the 17th century. It is generally agreed that the Dublin dated mark, similar to the London mark, was introduced about 1670. Later types of mark throughout Ireland followed the general pattern of British provincial types until 1840. Mileage marks were calculated from Dublin instead of London. The Dublin Penny Post was organized in 1773-4 and was extended to the outskirts of the city within a four-mile radius as a Twopenny Post.

In 1784, following an Act of Parliament, the Irish Post Office was separated from the British Post Office and remained a separate entity until 1831 despite the Act of Union in 1800.

1793-1815
During the Napoleonic Wars, there was one serious attempt to raise Ireland against the British with the support of the French navy and some French troops. The Irish leader, Wolfe Tone, landed in May 1798 and this led to a rebellion against British control. The rising was gradually suppressed during 1799 but not before large numbers on both sides had been killed.

By 1798 considerable improvement in communications with Britain had been achieved and the regular packet from Holyhead to Kingstown was sailing five times per week. The mail packets were very punctual and were vital to the government for the maintenance of contact with the local administration.

None of this was reflected in the postal history of the period. Ireland continued to operate as a separate unit until 1831, when it was combined again with the British Post Office.

Numerical cancellations of a design specific to Ireland were introduced in 1844, but otherwise the postal markings followed the normal pattern of a British provincial P0.

1850-71
During these years the question of Home Rule for Ireland dominated British politics, as it did for many years to come. There was constant unrest, and riots and murders took place as well as political assassination.

The Post Office, operated from London, remained aloof from these troubles and maintained an adequate service. This was supported by improvements in the standard of vessels used for the carriage of mail across the Irish Sea.

1871-1914
The difficulty of controlling Ireland continued unabated during the Victorian and Edwardian eras. The demand for Home Rule increased during this period and led to open revolution in 1916. Nevertheless, the postal service was maintained and British stamps continued to be used. The normal British postmark types were used and British pillar boxes were erected in Irish towns.

1914-18
Ireland, as part of Great Britain, was involved in World War I from 4 August 1914. British stamps continued to be used and normal services continued. However, on Easter Monday 1916 the Irish Republicans seized the Post Office and the rebellion broke out in earnest. Although this first rebellion was put down by British troops and the leaders were executed, the demand on resources for the maintenance of the war on the Western Front meant that Irish garrisons had to be reduced and it became possible for more trouble to be fermented.

A national parliament was established at the end of 1918 and it affirmed the independent status of Ireland in January 1919.

No adhesives were issued at this period, though some propaganda labels were produced.

A supply of British stamps printed by Harrisons (low values) or Bradbury Wilkinson (2s 6d, 10s) were overprinted in Ireland by Dollard Limited or Alex Thom & Co. A small number were also overprinted in England by Harrisons, but this was mainly on coils.

The definitive issue of Ireland began to appear in December 1922, but some British unoverprinted items, notably postal stationery and registered envelopes, continued to be used unoverprinted until they were superseded in 1924.

The first airmail connection with Britain began experimentally in May 1924, but all other mail was routed via London until 1939 when the regular Pan American Service from Foynes (near Shannon) to New York was introduced on 30 June. Imperial Airways followed on 5 August 1939 but the service terminated at the outbreak of war.

1939-45
Ireland remained neutral during World War II and the internal postal service operated normally. The names of most towns had by now been changed to their Gaelic equivalents and most of the handstamps too were changed during this period. The links by air for mail to the rest of the world were controlled by Britain, but Irish mail was accepted after censorship.

1946 to date
Although stamps have been inscribed EIRE since 1922, the official name of the territory did not take this form until the Republic of Ireland was formally established in November 1949. Since that date, Ireland has continued to issue stamps in the normal way.