He was the Norman commander at a naval battle in 1174 when a fleet of thirty-two ships from Cork, carrying armed men under the command of Gilbert, son of Turgerius, who was presumably an Ostman, attacked a group of Normans who had just plundered Lismore.
While he says that Dungarvan is named in the Book of Howth and in Bray's Conquest of Ireland,[3] he thinks that Youghal harbour was the more likely site.
After de Hereford was given large territories by Strongbow, he granted lands at what is now Castlewarden, along with Wochtred (Oughter Ard), both in County Kildare, to the Abbey of St Thomas in Dublin, leading to the foundation of St. Wolstan's Priory.
[4] In 1219, the Norman landowners, Warrisius de Peche, of the Manor of Lucan and Adam de Hereford, Lord of Leixlip, (Strongbow's right-hand man, and the Norman knight responsible for the construction of Leixlip Castle in 1172) granted to the brethren known as the order of the canons of St. Victor, the lands of St Katherine's, the Prior John Warrisius, Bishop of Meath Simon Rochfort and the Archbishop of Dublin Henry de Loundres are mentioned in the documents.
[5][6][7][8] Among the lands bestowed by Strongbow on de Hereford was half the vill of Aghaboe.