The county is rich in evidence of early human habitation.
 Portal tombs (sometimes called
dolmens) exist at Ballybrittas (on Bree Hill)
 and at
 — and date from the
Neolithic period or earlier. Remains from the
Bronze Age period are far more widespread.
 Early Irish tribes formed the Kingdom of Uí Cheinnsealaig, an area that was slightly larger than the current County Wexford.
County Wexford was one of the earliest areas of
Ireland to be
Christianised, in the early 5th century. Later, from 819 onwards, the Vikings plundered many Christian sites in the county.
 Wexford town became a Viking settlement near the end of the 9th century.
Wexford was the site of the invasion of Ireland by
Normans in 1169 at the behest of
Diarmuid Mac Murrough, King of Uí Cheinnsealaig and
king of Leinster (Laigin), which led to the subsequent colonisation of the country by the
The native Irish began to regain some of their former territories in the 14th century, especially in the north of the county, principally under
Art MacMurrough Kavanagh. Under
Henry VIII the great religious houses were dissolved, 1536–41; in County Wexford this included Glascarrig Priory, Clonmines Priory,
Tintern Abbey, and
On 23 October 1641, a major rebellion broke out in Ireland, and County Wexford produced strong support for
Oliver Cromwell and his English Parliamentarian Army arrived 1649 in the county and captured it. The lands of the Irish and Anglo-Normans were confiscated and given to Cromwell's soldiers as payment for their service in the Parliamentarian Army. At
Duncannon, in the south-west of the county,
James II, after his defeat at the
Battle of the Boyne, embarked for
Kinsale and then to exile in France.
County Wexford was the most important area in which the
Irish Rebellion of 1798 was fought, during which significant battles occurred at The
Battle of Oulart Hill took place near Oulart during the
Vinegar Hill (Enniscorthy) and
New Ross. The famous ballad
Boolavogue was written in remembrance of the Wexford Rising. At Easter 1916, a small
rebellion occurred at
Enniscorthy town, on cue with that in
World War II,
German planes bombed
 In 1963
John F. Kennedy, then
President of the United States, visited the county and his ancestral home at Dunganstown, near