The O Hanlons ruled the kingdom of Orior for over 1,000 years and had their headquarters in Tandragee where stands the ruins of a castle usurped from them in the 17th century. In the great rebellion of 1641 the O Hanlons destroyed their castle and when the lands and ruins were confiscated by the Crown the St. John family rebuilt the castle. It is now called Tayto Castle. Orior corresponded roughly to the present County Armagh but extended into County Louth.
The O Hanlons are descended from Colla Da-Crioch (one of three brothers Colla Uais, Colla Maen and Colla Da-Crioch) who were nephews of Fiacha, High King of Tara in the fourth century. The three Collas, as they were known, seized the High Kingship from him and slew him at Tailtean in County Meath, and installed Colla Uais as High King. He reigned for four years but was overthrown by Fiacha's son Muireadach and the brothers fled to Scotland. They returned three years later intending to challenge Muireadach, who, realising the threat they represented to him, suggested they turn northwards and win territories for themselves in Ulster. They gathered an army together in Connaught and invaded Ulster, completely routing the Ulstermen and killing King Fergus at Farney in Monaghan. They ravaged and destroyed Eamainn Macha and drove the Ulstermen east of Lough Neagh. From Derry in the north to Louth in the south and from Lough Neagh to Lough Erne the Collas made themselves the new kingdom of Oirghialla (Oriel). Their descendants are the MacMahons, O Carrolls, Maguires and O Hanlons.
Colla Da-Crioch took the eastern part of the territory, in Irish Oirthear and anglicized Orior and his descendants the O Hanlons settled in the location of the present city of Armagh.
It is recorded that when Saint Patrick came to Armagh and there built his first church in Ireland the land was given to him by a rich landowner named Dara. An inventory carried out by the English after the Plantation of Ulster notes that the lands of Navan Fort (Eamhainn Macha) belong to the church by gift of Patrick Dearraig O Hanlon. It is generally accepted by historians that this is the Dara who as the benefactor of Saint Patrick bestowed on him the hill on which to build his first church.
By the thirteenth century they had been pushed south to Loughgall. In the fourteenth century they had a castle, Castrum O Hanlon, at Lough Gilly. In the sixteenth century their lands at Tandragee are being confiscated by Queen Elizabeth under the Act of Confiscation and granted to Chatterton who was entrusted with the task of driving out all of the people of Orior. Chatterton was killed carrying out this task on the borders of Antrim but none of his family would take on the burden and the lands reverted to the Crown. On 1 December 1587 Queen Elizabeth regranted the lands to the last O Hanlon, Oghie, who gave an undertaking never to rise in rebellion. Oghie had four brothers, Patrick, Maoloughlin, Shane Óg and Feilimidh. He had four sons: Oghie Óg his heir, Toirdealbhach, Shane and Brian.
Sir Oghie married the sister of Hugh O Neill the Earl of Tyrone, and his heir Oghie Óg Married Margaret O Dougherty, sister of Sir Cahir O Doughtery of Inish Owen, County Donegal.When Oghie rose in abortive rebellion with 0 Dougherty in 1608, Sir Oghie, who sheltered his son for one night was deemed as having rebelled and we find it recorded that Sir Arthur Chichesler compounds with him for his lands.
Before that poor Sir Oghie must have been in dire straits, for in 1595, 0 Darby the poet wrote satirically:O Hanlon on the House of Mullagh whose suit of clothes was wretched when there.
And finally when on November 9th 1611, Sir Oghie is totally relieved of his lands and given a pension of £8.00 yearly the fall of the clan O Hanlon like other Irish clans is complete. Sir Oghie or as we should call him "The O Hanlon" must surely have died a broken and dispirited man.