Louth is bordered by the counties of Meath to the south, Monaghan to the west, Armagh to the north and Down to the north-east, across Carlingford Lough.

The county is steeped in myth, legend and history, and is a setting in the Táin Bó Cúailnge epic.

The whole area became part of the O'Carroll Kingdom of Airgíalla (Oriel) early in the 12th century under Donnchad Ua Cerbaill.

The Normans occupied the Louth area in the 1180s, forming the County of Oriel (Uriel or Vriell) out of the O'Carroll kingdom.

The Scottish army was repulsed from Drogheda but laid waste to much of the Anglo-Norman colony of Ireland including Ardee and Dundalk.

His army was finally defeated and Edward was killed in the Battle of Faughart near Dundalk, by a chiefly local force led by John de Bermingham.

He was created 1st Earl of Louth and granted estates at Ardee on 12 May 1319 as a reward for his services to the Crown in defeating the Scots.

3) stated "That every Irishman that dwell betwixt or amongst Englishmen in the County of Dublin, Myeth, Vriell [i.e. Oriel], and Kildare ... shall take to him an English surname of one town, as Sutton, Chester, Trym, Skryne, Corke, Kinsale; or colour, as white, blacke, browne; or arte or science, as smith or carpenter; or office, as cooke, butler ...".

In 1189, a royal charter was granted to Dundalk after a Norman nobleman named Bertram de Verdun erected a manor house at Castletown Mount.

[7][8][9] Until the late 16th century, 1596, Louth was considered part of Ulster, before becoming part of Leinster after a conference held at Faughart between the Chiefs of Ulster (Hugh O'Neill, Earl of Tyrone and Hugh Roe O'Donnell), on the Irish side, and the Ulster-born Miler Magrath, Anglican Archbishop of Cashel, and Thomas Butler, 10th Earl of Ormond on that of the English.

[10] The 16th and 17th centuries featured many skirmishes and battles involving Irish and English forces, as Louth was on the main route to 'the Moiry Pass' and the Ulster areas often in rebellion and as yet uncolonised.

[citation needed] In 1798, the leaders of the United Irishmen included Bartholomew Teeling, John Byrne, and Patrick Byrne, all from Castletown; Anthony Marmion from Louth Town and Dundalk, Anthony McCann from Corderry; Nicholas and Thomas Markey from Barmeath, and Arthur McKeown, John Warren, and James McAllister from Cambricville.

They were betrayed by informers, notably a Dr Conlan, who came from Dundalk, and an agent provocateur called Sam Turner, from Newry.

Louth is bordered by four counties – Meath to the south, Monaghan to the west, Armagh to the north, and Down to the northeast.

These two towns combined comprise approximately 58.9% of the county's total population, and are the 6th- and 7th-largest urban areas in Ireland respectively.

Louth has experienced a rapid rate of population growth since the 1960s, nearly doubling in size in the fifty years between the census of 1966 and that of 2016.

[25] In contrast to the other counties in the Mid-East Region, which are characterised by widespread migration from the Dublin area, Louth has one of the highest proportions of native residents in Ireland.

People from elsewhere in the Republic of Ireland accounted for just 13.9% of Louth's population in 2022, compared with 49.2% in neighbouring County Meath to the south.

However, extensive recordings of the dialect were made by German linguist Wilhelm Doegen for the Royal Irish Academy in 1928.

[28] An Irish language college, Coláiste Bhríde, was originally established in Omeath in 1912, but later moved to Ranafast, County Donegal.

Uniquely, the Cooley Peninsula had a sizable population of Presbyterian Gaeilgeoirí in the late 18th and 19th centuries, owing to its proximity to Ulster.

In 1808, Reverend William Neilson published "An introduction to the Irish language" to distribute to Presbyterian ministers in the area, as many in their congregations could not speak English.

[30] According to the Central Statistics Office (CSO),[31] the Catholic Church is by far the largest religious institution in County Louth, with 100,077 members.

Although Catholicism only recorded a 4.3% decrease, the share of County Louth's residents who identified as Catholic fell sharply from 81.8% in 2016 to 72.1% in 2022.

The local authority is Louth County Council, which has its offices in Dundalk, and provides a number of services including planning, roads maintenance, fire brigade, council housing, water supply, waste collection, recycling and landfill, higher education grants and funding for arts and culture.