[4] The two rival dynasties contested for control over Tír Eoghain until the battle of Caimeirge in 1241, where the O'Neills killed the MacLoughlin leadership.

[4] After 1241, the O'Neill house dominated and displaced other clans, using the disruption of the Norman invasion of Ireland in 1169 to their benefit and consolidating power.

Its collapse in 1333 allowed a branch of the O'Neill that had been on good terms with the Normans, Clandeboye, to step into the power vacuum and take control over large parts of eastern Ulster.

[6] After nearly a decade of warfare with the English forces in Ireland, Hugh O'Neill, Earl of Tyrone, surrendered in 1603, just days after the death of his enemy Queen Elizabeth.

Hugh continued to use his title after he fled to the Continent in the Flight of the Earls, although in the law of the Kingdom of Ireland it was forfeit by act of the Irish Parliament a year later.

[7] "The descendants of Prince Con MacBryan O'Neill, Tanist of Clanaboy, remained loyal, under every vicissitude, to the traditions of their house, and saved little out of the general wreck of confiscation.

They seemed to have preferred fulfilling the solemn pledge of their ancestor, Donald O'Neill, King of Ulster, to 'fight out as long as life should last' rather than adapt themselves to altered circumstances, as the descendants of Shane MacBryan had wisely done," according to Burke's Peerage.

He fought with the French against the British, the Austrians, and the Dutch (during the War of the Spanish Succession), in the celebrated Battle of Malplaquet, where he died on 11 September 1709.

Five years later, Sir Henry Farnham Burke, KCVO, CB, FSA, Somerset Herald stated in 1900 that "the only Pedigree at present on record in either of the Offices of Arms showing a lineal male descent from the House of O'Neill, Monarchs of Ireland, Kings of Ulster, and Princes of Tyrone and Claneboy, is the one registered in the fifty-ninth year of the Reign of Our Sovereign Lady Victoria, in favor of His Excellency Jorge O'Neill of Lisbon".

The king's younger son Aodh (Hugh) pushed into the territory known as the Fews and founded a lordship there based largely on the unlawful confiscation of considerable amounts of land belonging to the archbishop of Armagh.

Henry (1676-1745) should subsequently have recovered the confiscated lands; his relatives on the continent feared to send him back to Ireland to stake his claim and the property went by default and was sold in 1702–3.

[18][19] Following Henry's death, Felix O'Neill[20] (c1720-1792) was identified by contemporaries as the "person to whom the Lordship of the Fews in the North of Ireland in right and justice belongeth".

Felix left Ireland for a career in the Spanish Army and is well remembered for his rescue of Charles Edward Stuart ("Bonnie Prince Charlie") following the Battle of Culloden.

In the 2000s, Dr. Tulio José O'Neille of Buenos Aires in Argentina has come to light as the genealogically senior living heir of the O'Neill of the Fews.

[25] A contrary claim to the leadership of the dynasty comes from Spanish nobleman Don Carlos O'Neill, 12th Marquis de la Granja, who has been described as "the Prince of the Fews".

On his return to Spain in 1803 he was appointed to the Supreme Council of War (replacing Governor Miguel de Uztaraiz) and was awarded the title of the 1st Marques Del Norte two years later.

Arturo became a Lieutenant Colonel on 17 August 1828 in Bayamón, Puerto Rico and inherited the title of Marques Del Norte from his uncle.

O'Neill y O'Keefe was promoted to field marshal of the Royal Guard in 1828 and it was he who made the public announcement of the birth of a daughter to the King in 1830, namely the future Isabel II of Spain.

During Shane's lifetime, he made claim to the legitimate patrimony of these children and thus they were raised in the courts of their various maternal grandfathers and aunts upon his death.

When they invaded the brothers took the English and the O'Neill chiefs by surprise and created a large sphere of control in eastern Ulster, allied with the MacDonald's of Antrim.

[31] The earl succeeded in capturing and imprisoning another three over the remainder of the decade until there were only two possibly three of the brothers and nephews hiding out in the Glenconkeyne forest in eastern Tyrone.

[33] Hugh McShane O'Neill reigned as chief until 1622 and his sons and grandsons served as the chieftains of the family and were active in the wars and politics of Ulster, Ireland, and Spain for the next two centuries.

Brian's son Edmond was granted control of Lisdawericke, Megin, Cnoghan, Tollohiny Dirrilghta, Knockmcgallcrum & Gortnesillagh.

Two decades later, his son the new Chief, Brian Og (the Younger) led the clan in service of the O'Neill regiments supporting King James II.

After the defeat of the Jacobite forces, the family was "attainted" as Irish rebels in 1693, and Brian "Og" left with the Army of King James II and went into exile in France.

Today the clan recognizes McShane, Johnson, Johnston, and Shane as elements of the family and are still active and viable in Ulster, America, and Australia.

[48] The red hand is explained by several legends, with a common theme of a promise of land to the first man to sail or swim across the sea and touch the shores of Ireland.

O'Neill cuts off his left hand and throws it onto the beach before the other challengers can reach the shore, becoming the first to touch land and win all of Ireland as his prize.

According to Leabhar Chlainne Suibhne, Anradhán, son of Aodh Athlamháin, quarrelled with his elder brother, Domhnall, ancestor of the O'Neills, and left Ireland for Scotland.

[51] Leabhar Chlainne Suibhne, Dubhaltach Mac Fhirbhisigh's genealogies, and Cú Choigcríche Ó Cléirigh's pedigrees specifically state that the MacSweens were descended from Anradhán.