Lacking the strength in depth enjoyed by England and Scotland, Irish internationals of this era started younger and their careers lasted longer than their English or Scottish contemporaries.

Before then the Ireland team selected its players exclusively from the Irish League, in particular the four Belfast-based clubs, Cliftonville, Distillery, Glentoran and Linfield.

On 28 March 1903, aged 38 years and 283 days, he scored the opening goal in a 2–0 win against Wales and became the oldest goalscorer in Ireland's history.

Following the end of hostilities, the British Home Championship resumed in October 1919, opening with Ireland taking on England at Windsor Park.

However they did have a number of excellent match performance including beating England 2–1 at Windsor Park on 10 October 1923 with a team featuring Tom Farquharson, Sam Irving, Bobby Irvine and Billy Gillespie.

However, in the 1920s there were occasions when Ireland played other teams, including France, Norway and South Africa, for various reasons, such as the number of amateur players involved, the status of these internationals has been disputed.

On 2 February 1930 Ireland beat Wales 7–0 with Joe Bambrick, playing at his home club ground scoring six of the seven goals.

[7]: 245 However Ireland spent the remainder of the decade in the bottom half of the table, only managing to avoid last place on three occasions.

Following war breaking out in Europe, the British home championship was again suspended with Ireland finishing the 1938–39 competition where they had spent most of the last two decades, at the bottom of the table, having lost all their games.

[11] At the same time, the IFA continued to organise its national team on an all-Ireland basis, regularly calling up Free State players.

[12][13] During this era at least one Northerner, Harry Chatton, also played for the Irish Free State and from 1936, the FAI began to organise their own all–Ireland team.

During the Second World War all home internationals were suspended, however, during this period Ireland played an unofficial match against a combined services eleven, which was effectively a Great Britain side containing Matt Busby, Stanley Matthews, Tommy Lawton and Stan Mortensen.

The English FA requested each association to select only players from its jurisdiction, "quoting the International Federation rule to that effect".

On 27 November, seven players born in the 26 counties, including Johnny Carey, Peter Farrell and Con Martin, played in the IFA side's 0–0 draw with Scotland.

From then until the 1949–50 season the IFA regularly selected five to seven players born in the Free State and were rewarded with some respectable results, including a 2–0 win against Scotland on 4 October 1947 and a 2–2 draw with England at Goodison Park on 5 November the same year.

Ireland hosted the first ever World Cup qualifier in which a home nation side competed, losing 2–8 to Scotland in Belfast, and eventually finishing bottom of the group only managing to take a point, away to Wales.

The team included four players – Tom Aherne, Reg Ryan, Davy Walsh and the captain Con Martin – who were born in the Irish Free State, and all four of whom had previously played for the FAI international team in their qualifiers and as a result had played for two different associations in the same FIFA World Cup tournament.

[22] Rule 35(b) of the FAI articles provided that players based in the Republic would be denied clearance certificates for transfers abroad unless they gave a similar undertaking.

At FIFA's 1953 congress, its Rule 3 was amended so that an international team must use "that title ... recognised politically and geographically of the countries or territories".

On 17 March 1900, Saint Patrick's Day, Ireland played their first game in Dublin, losing 0–2 at Lansdowne Road to England.

[35] Ireland's initial logo was a stylised Celtic cross with a harp in the centre, which in a modern form is used by the current team, however this had been replaced in the 1930s until the 1950s with a Shamrock badge.

See Category:Pre-1950 IFA men's international footballers Selection was the responsibility of a committee, with no individual manager in the modern sense.

During the preparations for the 1928 Olympic Football Tournament, FIFA ruled that all its member associations must provide "broken-time" payments to cover the expenses of players from the country who participated.

In response to what they considered to be unacceptable interference, the football associations of Scotland, England, Ireland and Wales held a meeting at which they agreed to resign from FIFA.