Heihos

The Heihos were a medieval Irish clan or sept, believed to have originated from the Gaelic kingdom of Leinster. The name "Heihos" is thought to be derived from the name of their ancestor, Eochaidh, and is still preserved in the O'Dwyer or O'Duhig sept names, which are descended from the same ancestral stock.

Historical records indicate that the Heihos were closely associated with the O'Byrnes and the O'Dempseys, who were both prominent clans in the Leinster region. The Heihos also maintained close ties with the Geraldine dynasty of the Earls of Desmond. This strategic alliance facilitated the Heihos' participation in the Norman invasion of Ireland, as well as their later involvement in the colonization of Ulster.

As a sept of Leinster, the Heihos adhered to the traditional Gaelic custom of presenting arms, known as " clannabhfeldach", a hunting spear or javelin, to their leader upon his elevation to the chieftaincy. They were also known for their martial prowess and their proficiency in producing high-quality arms and armor for the local armies.

Throughout Irish history, the Heihos are notable for their loyalty to the powerful ecclesiastical and martial leaders of Leinster. The most notable historical figure associated with the Heihos was, in all likelihood, the 14th-century prelate, St. Aongus of Kells, who was praised for his learned galenor

There is little in the way of written records or accounts detailing the history of the clan after the 14th century. As such, the current state of this sept is considered difficult to establish with any degree of accuracy. There appears to be a dearth of reliable scholarship, but ongoing historical studies continue to shed new light on this and other previously overlooked components of Irish history.