Transport on a country-wide scale began in 1710 with the introduction by the General Post Office of mail coaches on the main routes between towns.
In 1715 the Irish Parliament took steps to encourage inland navigation, but it was not until 1779 that the first 19 km (12 mi) section of the Grand Canal was opened.
Despite these improvements huge areas of Ireland still relied on a basic road system; turnpikes were still slow and canals were expensive.
The contractor was William Dargan, called "the founder of railways in Ireland", due to his participation in many of the main routes.
On 9 October 1834 the locomotive Hibernia brought a train the full route from the Westland Row terminus (now Dublin Pearse) to Kingstown.
The entire route forms part of the present day Dublin Area Rapid Transit electrified commuter rail system.
At its height, in the thirty or so years prior to World War I, the GNR(I) covered a large area of Ireland between Dublin, Belfast, Derry and Bundoran.
This left some useless stubs within the Republic, such as through Pettigo station; 13 km (8 mi) from the border to Bundoran and Monaghan to Glaslough.
The GNRB was abolished on 1 October 1958, when it was split between the Ulster Transport Authority and Córas Iompair Éireann in Northern Ireland and the Republic, respectively.
The Midland Great Western Railway (MGWR) was incorporated in 1845 to build a line parallel to the Royal Canal between Dublin and Longford.
Additionally, the Carrickfergus Harbour Junction Light Railway 2 km (1 mi); was incorporated in 1882, opening in 1887 and was worked by the Northern Counties Committee.
The Irish Civil War was to take a much heavier toll on the railways in the newly born Irish Free State (Saorstát Éireann), as the Anti-Treaty IRA systematically targeted them and the Free State had to build a network of fortified blockhouses to protect the railways.
Partition however, would eventually exact a heavy toll on the cross–border routes (intrinsic to the County Donegal rail network).
The deteriorating quality and frequency of service discouraged rail travellers, whose numbers were also diminishing due to steadily increasing emigration.
Railways in the Republic were converted to diesel locomotive traction early, and swiftly, due to the run down nature of many of the steam engines, lack of coal, and a desire for modernisation.
The main routes from Dublin to Belfast, Sligo, Galway and the West of Ireland, Limerick, Cork and Kerry, Waterford and Wexford survived.
South of the Sandyford depot, decisions taken by CIÉ and Dún Laoghaire–Rathdown County Council, to sell the trackbed through Foxrock and allow houses to be built on it near Shankill respectively have made integrating this route into the Luas system difficult.
Also, 1976 saw the introduction of a small fleet of 18 high-speed diesel-electric locomotives built by General Motors Electro-Motive Diesel at La Grange, Illinois.
These 2,475 hp (1,846 kW) units, 071 Class, were capable of speeds of 145 km/h (90 mph) and immediately began operating express services such as the Cork-Dublin line.
A major disaster occurred on 1 August 1980, when 18 people were killed and 62 injured in a rail accident in Buttevant on the main Cork-Dublin line.
This structure was incapable of surviving a high speed crash and did not come near to the safety standards provided by modern (post 1950s) metal bodied coaches.
This accident led to a major review of the national rail safety policy and resulted in the rapid elimination of the wooden-bodied coaches that had formed part of the train.
The decision to purchase a new fleet of modern InterCity carriages based on the British Rail Mark 3 design was quickly made.
These coaches, an already well proven design, were built by BREL in Derby, England and, under licence, at CIÉ's own workshops at Inchicore in Dublin between 1980 and 1989.
34 new locomotives (designated 201 Class) were purchased from General Motors, including two for Northern Ireland Railways (NIR).
DART and Commuter stations were also upgraded, allowing access for people with disabilities with new lifts at footbridges and lengthened platforms to accommodate 8-car sets.
Iarnród Éireann placed orders for 67 InterCity carriages in 2003 and for 150 "regional railcars" (diesel multiple unit) in 2004.
In the face of long journey times and a frequent (and generally faster) bus service, the route's future remains in some doubt.
The derogation ended on 14 March 2013, when Iarnród Éireann was split in two sectors: Railway Undertaking and Infrastructure Manager.
[8] In relation to fleet expansion, orders of DARTs were suspended indefinitely in October 2009, but Dublin suburban routes are almost at capacity.