Duleek began as an early
Christian monastic settlement.
Saint Patrick established a
bishopric here about 450 AD, which he placed in the care of
Saint Cianán on 24 November 489. The place was sacked several times by the
Norsemen between
830 and
1149 and was also pillaged by the
Normans in
1171. In April
1014, the bodies of
Brian Ború and his son lay in state in Duleek on their way to
Armagh. The original monastery settlement is reputed to be the place where Saint Patrick and several contemporaries spent the winter period while compiling the Seanchas Mór, the first written compiled form of the ancient
Brehon Laws of Ireland, in the fifth century. The 12th century saw the reconstitution of the original monastery as Saint Mary's Abbey and the subsumption of the
Diocese of Duleek by the
Diocese of Meath. The first
Anglo-Norman Lord of Meath,
Hugh de Lacy, established a manor and constructed a
motte castle at Duleek. In
1180, he granted Saint Cianán's Church, together with certain lands, to the
Augustinians. The churchyard of the now disused
Church of Ireland church occupies part of the site of the early monastery. On the opposite side of the village, in the town land of Abbeyland, close to the river
Nanny and Duleek House there are ruins of the Grange of Saint Michael. This grange was established in about 1172 by Augustinian monks from
Llanthony in
Monmouthshire; the lands were granted to them by the De Lacy family. The village's four crosses and the lime tree on the village green are reminders of Duleek's links to the struggle between
William III and
James II and to wider European unrest at the time of
Louis XIV. A 10th century high cross is located just north of the church. Scenes from the New Testament are located on its west side this cross, another segment of a cross is located inside the church. Another cross, the
Wayward Cross, was erected in 1601 by Janet Dowdall in memory of her husband,
Sir William Bathe of
Athcarne Castle, outside the village. During World War II, or
The Emergency, German bombers accidentally struck the village on 1 January 1941, causing minor damage without casualties.
The Duleek Heritage Trail covers a number of sites in the village centre and was "conceived as a series of stepping stones through the village" and its history. {{Historical populations|state= ==Transport==