Biography

A son of Jocelyn de Angulo

Jocelyn de Angulo

-Biography:De Angulo was one of fifty knights serving under Hugh de Lacy upon the latter's grant of Meath by Henry II in 1172. Jocelyn was awarded the barony of Navan by de Lacy...

, Gilbert held the barony of Machaire Gaileng (Morgallion and Ratoath

Ratoath

Ratoath is a town in the barony of the same name, County Meath in Ireland. The town is centered on the point where the R125 and R155 regional roads meet. In the 1996 census, the population was recorded as 1,061. In the 2006 census, it was 7,249...

). Upon his rebellion in 1195 all his lands were forfeited - given by Walter de Lacy

Walter de Lacy

Walter de Lacy was Lord of Meath in Ireland and Ludlow in Shropshire in the Welsh Marches.- Life :With his father Hugh de Lacy, Lord of Meath he built Trim Castle , Trim, County Meath....

 to his brother, Hugh, about 1198 - and Gilbert and his brothers Phillip and William outlawed.

Gilbert fled English jurisdiction and sought service with King Cathal Crobhdearg Ua Conchobair of Connacht

Connacht

Connacht , formerly anglicised as Connaught, is one of the Provinces of Ireland situated in the west of Ireland. In Ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for...

. In return, Cathal granted him lands at Máenmaige

Máenmaige

Máenmaige was a originally a kingdom, later termed a trícha cét, and in Anglo-Norman times a cantred, which formed the barony of Loughrea.-Early historic rulers:It was first under the control of Ui Fhiachrach Fionn, and later by the Uí Maine...

, in western Uí Maine. Upon his pardon in 1206, King John of England

John of England

John , also known as John Lackland , was King of England from 6 April 1199 until his death...

 confirmed him in lands granted by King Cathal and made him a grant of other lands. Brought back into John's favour, he assisted Cathal in the construction of Caeluisce, near Ballyshannon

Ballyshannon

Ballyshannon is a town in County Donegal, Ireland. It is located where the N3 and N15 cross the River Erne, and claims to be the oldest town in Ireland.-Location:...

, in 1212. It was attacked and burned the following year, Gilbert being killed during the attack.

Gilbert also appears to have held land in Uí Lomain and Cineal Fheicin/Muntir Mailfinnain. However, as all his lands were held by new owners subsequent to Richard Mor de Burgh

Richard Mor de Burgh

Richard Mór de Burgh, 1st Lord of Connaught , Justiciar of Ireland.-Background:De Burgh was the eldest son of William de Burgh and a daughter of Domnall Mór Ua Briain, King of Thomond. His principal estate was in the barony of Loughrea where he built a castle in 1236 and a town was founded. He also...

's settlement of Connacht in the 1230s, it appears his family had by then died out in the male line.

Descendants of his brother William adopted the Irish surname Costello

Costello

Costello is a surname in the English language. The name is an Anglicised form of the Irish Mac Oisdealbhaigh, meaning "son of Oisdealbhach". The Irish Oisdealbhach is derived from two elements: the first, os, means "deer"; the second element, dealbhach, means "in the form of", "resembling"...

.

Annalistic references

From the Annals of the Four Masters

Annals of the Four Masters

The Annals of the Kingdom of Ireland or the Annals of the Four Masters are a chronicle of medieval Irish history...

:

• 1193 - Inishcloghbran was plundered by the sons of Osdealv, and the sons of Conor Moinmoy.

• 1194 - Gilbert Mac Costello marched, with an army, to Assaroe, but was compelled to return without being able to gain any advantage by his expedition.

• 1195 - Cathal Crovderg O'Conor and Mac Costelloe, with some of the English and Irish of Meath, marched into Munster, and arrived at Imleach Iubhair (Emly) and Cashel. They burned four large castles and some small ones.

• 1211 - An army was led by the Connacians, at the summons of the English bishop and Gilbert Mac Costello, to Assaroe; and they erected a castle at Cael-uisge.

• 1212 - Gilbert Mac Costello was slain in the castle of Cael-uisge; and the castle itself was burned by O'Hegny.

Family tree

Joycelyn de Angulo, fl. 1172.
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Gilbert Phillip William/William Mac Coisdealbhaigh
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Miles Bregach Mac Coisdealbhaigh
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Hugo, d. 1266? Gilbert Mor Phillip, fl. 1288.