[3][1] His paternal grandparents were Sir Hugh McManus O'Donnell, an Ulster chieftain, and Scottish noblewoman Fiona "Iníon Dubh" MacDonald.

[4] His maternal grandparents were Irish peer Henry FitzGerald, 12th Earl of Kildare,[3] and English noblewoman Frances Howard.

His father's paternal family were the Gaelic Irish O'Donnell clan of Tyrconnell, who claimed descent, via Conall Gulban of the Cenél Conaill, from High King Niall of the Nine Hostages.

[4] On 14 September 1607, due to increasing hostility from the government, Rory and his wartime ally Hugh O'Neill, Earl of Tyrone, fled from Ireland along with ninety of their followers.

[3][20] Bridget was pregnant at the time; a few months after the flight, she gave birth to Hugh Albert's younger sister Mary Stuart O'Donnell.

[21][22] The refugees hoped to reached Spain, but were turned away due to Philip III's fears of violating the Treaty of London.

They had "lost all their possessions to come [to Flanders]", and they maintained Hugh Albert for "a full year and six months" at their own expense.

After the earls left for Rome, another nurse, named Anna ny Madden supplanted Caecilia.

The O'Gallaghers bemoaned that they had "no other consolation except this child, or means of support, or income", and lamented to the Archduke that they "had nothing to eat except what your Highness with your wanted kindness is pleased to grant".

[26] Tyrone petitioned for Nuala and Rosa to be relocated back to the Spanish Netherlands to alleviate their deprivation and allow them to look after the O'Donnell cousins.

[32] For the next two years, Rosa and Nuala repeatedly petitioned the Spanish government to allow them to reunite with their nephews in Flanders.

[33] Phillip III instructed ambassador Castro to "calm [Rosa] and divert her from this purpose and console her in what manner seem[s] best to you".

[26][35] It was recorded that from 1615, the "Conde de Tyrconnell" and Don Hugo O'Donnell were in the receipt of a modest pension from the Archduke.

Around this time, Hugh Albert was attached as a page to the court of the Infanta Isabella (the Archduke's consort).

[43][44][45] In 1627, rumours abounded of another Spanish Armada, with Hugh Albert to play a major role in leading the Irish.

[46] The Archbishop of Tuam Florence Conry arranged for Mary to be married to Shane O'Neill, 3rd Earl of Tyrone.

[21] The relations between the O'Neills and the O'Donnells had become strained after the war's end, and Conry hoped a unifying marriage would allay hostilities between the noble families.

[47] In adult life, Hugh Albert styled himself Earl of Tyrconnell and Donegal, Baron of Lifford, Lord of Sligo and Lower Connaught, and Knight Commander of the Order of Alcántara.

[1] In 1641, when the Irish rose in arms to oppose the Parliamentarians, eyes turned to Hugh Albert, who was then a Spanish general of reputation.

His military rank and experience, coupled with his claim as a descendant of the Gaelic nobility and his association with Celtic prophecies, all contributed to this.

[52][53][49] Anna-Margaret's eldest brother was Albert Maximilian de Hennin, who was an ally to Owen Roe O'Neill.