From Irish Roots, 1995, #1, p22, 'Surnames of County Mayo':
Gibbons (Mac Giobain) This Norman sept is a branch of the Burkes of Mayo who settled in the fertile area of the south and centre of the modern county in the early of 1200s. the progenitor of the Gibbons was one Gilbert Burke the great grandson of William De Burgo (died 1205) from whom the Burkes of the west of Ireland are said to be descended. The townlands of Ballymacgibbon and Belleogevan take their names from the sept. Cardinal James Gibbons 1834-1921, Roman Catholic Archbishop of Baltimore, USA was of Mayo parentage.

From Irish Roots, 1994 #2, page 25, 'Surnames of County Tipperary': William de Burgh, who died in 1205, was one of the most extraordinary of the Norman lords who pushed their way across the country. Various descendants of his established families in Tipperary, Limerick and Connacht. The territory of Clanwilliam was named after him. In the context of Irish roots, the most interesting holder of the Bourke family name was Sir John Bernard Bourke of Burke's Peerage etc., whose father John Bourke (1787-1848), also a noted genealogist, was born at Elm Hall in the north of the county.

From Irish Roots, 1994 #1, page 27, 'Surnames of County Galway': The Norman families who accompanied the de Burgos included not only the Galway Tribes, but also the Berminghams who later took the title Lord Athenry. Many of the de Burgo descendants were to take names other than that of Burke which most adopted. For example, the Jennings family is really a branch of the de Burgos. The form Jennings comes from the Irish MacSeoinin, or son of John. They are descended from a John Burke. The MacRedmonds are descended from Redmund Burke but most of them have dropped the Mac. It is sometimes thought that the Galway name MacHugo is a variant of MacHugh. It is, in fact, a separate family descended from Hugo Burke just as MacDavie indicates an ancestor named David Burke.
The name Burke is one of the most numerous among Galway surnames. The Norman progenitor of the family was William FitzAdelm de Burgo who was sent to Ireland with Hugh deLacy and in 1179 received a grant from King Henry II of England of large tracts of Connacht. About 50 years later his son Richard built a castle at Galway as part of his campaign to take possession of the lands thus bestowed on his father. The surname was to spread rapidly. It became de Burgh, Burke and Bourke. But the families subdivided and became Hibernicised. They even adopted among their subsepts names such as macDavie, MacHugo, MacRedmond, MacGibbon, and MacSeoinin. The major division was between the Burkes of MacWilliam Uachter in Galway and of MacWilliam Iochtar in Mayo.
Though the Burkes, or de Burgos, founded Galway city their followers, later known as the Tribes, soon tried to cast off their overlordship. Indeed the charter of 1484 issued to Galway by Richard III was to break the suzerainty of the Burkes who were not allowed to enter the city without the license of the Mayor. The only Burke to become the Mayor of Galway was Dominick Burke in 1737 until the Corporation was in decline in the 1820s. The major branch of the family in County Galway were the Clanricarde Burkes who were chieftains of their name and descendants of Rochard Og Burke who died in 1387. The title Earl of Clanricarde was given to the head of the family by Henry VIII in 1543. Portumna became the principal seat of the Clanricardes. Junior branches had seats at various places in Galway. They occupied many of the late medieval tower houses but later built residences such as St Clerans, near Craughwell or the Castle at Glinsk. They were to play a very important role in the 17th century wars from which the Clanricardes emerged defeated but still with very substantial estates. The most notable Galway Burkes were probably Robert O'Hara Burke of St Clerans, the noted explorer in Australia who died in 1861, and the famous Dominican preacher and writer, Father Thomas N. Burke who died in 1883 and whose statue stands near the entrance to the Claddagh in the city.

Weis' "Ancestral Roots. . ." (177B:8). Does not identify his parents. Possibly also the father of Hubert de Burgh (RIN 4854*), justiciar of England under KING EDWARD III, but there are also other possibilities and no proof has surfaced as to his parentage.

The first of the Bourkes, came into Ireland in the year 1172, established a settlement there at Athassel, near Cashel; where he founded a Priory in 1200, and there formed a vault for himself and his posterity. 97

Elder brother of Hubert de Burgh. That he was brother of Hubert is proved by an entry in the Patent Roll of 1234 where Hubert is called Richard de Burgh's uncle: Richard was William's son. He arrived in Ireland with prince John who was then Count of Mortain, and received many grants of land there about 1185. These included the manor and castle of Tibraghny, Co Kilkenny, Ardpatrick, Co Limerick and the Tullagh, co Dublin. He was also granted the manor of Esclon in co Limerick in 1204. In 1200 he founded the Abbey of Athassel, now called the Abbey of Golden, near Cashel, co Tipperary, for the Augustinian monks. In 1200 he began the first of his many campaigns in Connacht which earned him the designation of William 'Concur" the Conqueror, given to him by the Irish Annals. William at first took up the cause of Cathal Carrach O Conor against his rival Cathal Craobhdearg O Conor, and the latter fled into Ulster, and Cathal Carrach O Conor was made king of Connacht in his place.
In 1202 however, William de Burgh took side with Cathal Craoghdearg o Conor against Cathal Carrach O Conor who was slain in a skirmish near the Abbey of Boyle. William de Burgh and Cathal Craobhdearg O Conor then proceeded together to Cong Abbey where they spent Easter together. William de Burgh having by agreement billeted his soldiers with the various clans throughout Connacht. However a false rumor of William de Burgh's death got about and the billetted soldiers were massacred by the host clans. The toll was over 900. William retreated to Limerick where he was granted the castle and manor to Castleconnel by King John.
In 1203 William began a campaign of reprisal against Cathal Craobhearg O Conor. He plundered Clonfert Abbey and left a garrison at Meelick CAstle. Thence he marched northward by Knockmoy to Mayo Abbey, plundering all along the route, and from Mayo he proceeded to Cong. The King of Connacht, Cathal Craoghdear complained to King John and in October of that year, William was summoned to England to answer to King John in person, why he had made war against O Conor, who was then since the Treaty of Windsor in 1185 a vassal of the English Crown. William justified his action to the King, with the help and influence of his brother, Hubert, who made an order dated 16 Sep 1204 directing Melier FitzHenry, Justiciar of Ireland to restore to William de Burg all his castles and lands in Munster, which the Justiciar had taken possession of in the King's name.
The de Burgh lands in Connacht were to be retained by the King until he had received further explanation from William. William returned to Ireland towards the close of 1204 and his death occurred early in 1206 as the Annals of the Four Masters record "he died of a singular disease too shameful to be described." He was buried in the monastery of Athassel, which he had founded and had issue by his 2d wife, Aoife, daughter of Donal Mór O Brien, King of Thomond, four sons.9

William de Burgh (c. 1160–1204) was born in the village of Burgh Castle, Norfolk, East Anglia, Kingdom of England and died at Athassell Abbey, Golden, County Tipperary, Munster, Ireland.
William took his surname from the village of Burgh Castle, Norfolk, England. Very little can be ascertained about his background other than his family were minor gentry, and that his probable younger brother was Hubert de Burgh, later Earl of Kent.
William apparently arrived in Ireland in 1185 among the retinue of Prince John of England, son of Henry II of England and Eleanor of Aquitaine. John apparently appointed him Governor of Limerick. Within a few years he was granted the manors of Kilsheeland and Ardpatrick, and in time, the castle of Tibraghty in County Kilkenny.
Sometime in the 1190s, William married a daughter of Donal Mor mac Turlough O'Brian, King of Thomond (died 1194). This alliance probably took place during the reign of his son, Murtough, as up to the time of his death Donal had being at war with the Normans. At any rate no more wars are recorded between the two sides for the rest of the decade.
In 1200, "Cathal Crobderg Ua Conchobair went into Munster, to the son of Mac Carthy and William Burke to solicit their aid." This marked the start of de Burgh's interest in the province. Though King of Connacht Cathal Crobderg Ua Conchobair (reigned 1190–1224) faced much opposition, mainly from within his own family and wished to engage Burke's aid to help secure his position. The following year William and Ua Conchobair led an army from Limerick to Tuam and finally to Boyle. Ua Conchobair's rival, Cathal Carragh Ua Conchobair marched at the head of his army to give them battle but was killed in a combined Burke/Ua Conchobair onslaught after a week of skirmishing between the two sides.
William and Ua Conchobair then travelled to Iar Connacht and stayed at Cong for Easter. Here, William and the sons of Rory O'Flaherty conspired to kill Ua Conchobair but the plot was foiled, apparently by holy oaths they were made to swear by the local Coarb family. However, when de Burgh demanded payment for himself and his retinue, battle finally broke out with over seven hundred of de Burgh's followers said to have being killed. William, however, managed to return to Limerick.
The Annals of the Four Masters recorded his passing in 1204:
"William Burke plundered Connaught, as well churches as territories; but God and the saints took vengeance on him for that; for he died of a singular disease, too shameful to be described."
He was survived by his sons Richard Mor de Burgh (d. 1242), Hubert de Burgh, Bishop of Limerick (d. 1251), Sheriff William de Burgh (d. 1247) and an apparently illegitimate son, Richard de Burgh.
The senior male line of the family came to an end with the murder of William Donn de Burgh, 3rd Earl of Ulster, in 1333. A junior branch later gave rise to the Earls of Clanricarde.