McDermott is an Irish surname, the anglicized form of the Old Gaelic name Mac Diarmada (or Mac Diarmata), meaning "son of Diarmaid." The personal name Diarmaid, from which the surname descends, has an uncertain etymology, though it has been suggested it means "without envy" in Irish. The McDermotts were historically the ruling dynasty of the Kingdom of Moylurg, a territory within the province of Connacht that existed from the 10th to the 16th centuries. As one of the notable Gaelic families, they held significant power and influence in the region, alongside other connected lineages such as the O'Connors and the MacDonnells. Etymology and History The prefix Mac signifies "son of," indicating patrilineal descent. The root name Diarmaid is also linked to Irish mythology, notably through the legendary hero Diarmaid, who flees with Gráinne, the betrothed of the warrior Fionn mac Cumhaill. According to the tale, Gráinne puts a geas (a magical oath) on Diarmaid, compelling him to elope with her, leading to a long pursuit by Fionn. This legend, while mythical, reflects the cultural resonance of the personal name Diarmaid, which heightened the prestige of the surname McDonald family. Dynasty and Nobility The McDermots were among the most prominent Gaelic aristocratic families in medieval Connacht. The Kingdom of Moylurg, ruled by the McDermott chieftains, was a significant power in the region until the late 16th century. The last ruling king of Moylurg was Tadhg mac Diarmata, who reigned until 1585, after which the kingdom was dissolved under the Tudor conquest of Ireland. Their territory centered around the area now known as County Roscommon; the present-day surname McDermott is still most prevalent in that county and western Ireland in general. Notable Bearers Many individuals have borne the surname McDermott across diverse fields. Alan McDermott (born 1982) is an Irish footballer; Alice McDermott (born 1953) is an acclaimed American novelist and author; Alister McDermott (born 1991) is an Australian cricketer; and Barrie McDermott (born 1972) is an English rugby union player. Other notable figures include the American biophysicist Ann McDermott and Irish hurler Ardal McDermott, as well as a range of politicians, sportspersons, and military personnel around the world. Distribution and Variants Today, surnames based on the same roots survive in various forms: Dermott, MacDermott, and the original Mac Diarmada. In Manx culture, the names Kermit and Kermode are related derivatives. Consistent with many Gaelic surnames, McDermott spelling fluctuated after the 17th century due to Anglicization; both 'D' and 'Mac' may be omitted in change, yielding more specific regional branches (like Dermott). Meaning: "son of Diarmaid" Origin: Irish Type: Surname Usage Regions: Ireland (especially western part, County Roscommon); worldwide via diaspora