Although Down was the first area in the north to be captured by the Normans, when John de Courci marched north from Dublin with 300 or so men in 1177, they were soon assimilated and the region retained its largely Gaelic character until the seventeenth century when, even though the area was not formally included in the Plantation of Ulster, there was a large influx of English and Scottish settlers. Presbyterians and members of the Church of Ireland now constitute about two-thirds of the population.
The Mourne mountains in the south of the county form one of the most beautiful areas in Ireland.
The grave of St Patrick is reputedly in the grounds of the cathedral at Downpatrick.
Under the organizational reforms carried out in Northern Ireland in 1973, the county ceased to exist and was divided into various smaller administrative units. Identification with the old county continues in the daily lives of the people.
Reflecting the county's history, common surnames here include Campbell, McAleavey, Hamilton, O'Neill, McCartan, Dodds and Gilmore. Although the surname McGuinness, from which the famous drink gets its name, originated here, the surname is now less common in Down than further south and west. The previous President of the Republic of Ireland, Mary McAleese, comes from the south of the county.