Meath is traditionally said to have been created in the first century by Túathal Techtmar. The Uí Enechglaiss was an early dynasty of the region. An ogham stone found south of Slane suggests they controlled that area in County Meath. Along with the Uí Failge and Uí Bairrche, they belonged to the Laigin, but may also be associated with the Iverni.
During the early 6th century, they were driven away from their original homeland in Kildare and over the Wicklow Mountains by the Uí Néill, whose sept, the Clann Cholmáin, took their place. The Uí Enechglaiss were later based in and around Arklow well into the historic period. Its ruling dynasty later took the surname O'Feary.
After the kingdom's collapse in the 12th century, the dynasty of the Ua Mael Sechlainn or O Melaghlins were forced west and settled on the east bank of the River Shannon.