Like many Irish Catholics and especially Gaelic Irish Catholics, O'Neill felt threatened by the Protestant English government of Ireland. In particular, they were aggrieved at Catholic exclusion from public office and the continual confiscations of Catholic-owned land. Another reason pressing him into desperate action was that Phelim was deep in debt.
Plot This fear reached its high point in the late 1630s and early 1640s, when
Thomas Wentworth, Lord Deputy for
Charles I, was known to be planning widespread new
plantations. A crisis point was reached in 1641, when the Scottish Covenanters and English
Long Parliament threatened to invade Ireland to finally subdue Catholicism there. In this atmosphere of fear and paranoia, Phelim O'Neill became involved in a plot hatched by fellow Gaelic Irish Catholics from Ulster, to seize
Dublin and swiftly take over the other important towns of Ireland. After this, they planned to issue their demands for full rights for Catholics and Irish self-government in the King's name. O'Neill's role was to take towns and fortified places in the north of the country whereas Maguire was tasked with seizing
Dublin Castle. by
Daniël Mijtens O'Neill was a latecomer to the plot, brought into it by
Lord Maguire in early September 1641. On 23 October 1641 he surprised
Lord Caulfeild in
Charlemont Fort. O'Neill was instrumental in shaping many of the political objectives of the rebellion. He rapidly assumed command of the Ulster rising.
Outbreak However, the plan to take Dublin was bungled by two conspirators, Maguire and MacMahon, who were captured by the authorities. O'Neill went ahead and started the rebellion in the north, capturing the important fort of Charlemont but quickly found that he could not control the Irish Catholic peasantry he had raised. These people, many of whom had been displaced during the
Plantation of Ulster, began attacking the Scottish and English Protestant settlers with varying intensity over a period of 5 months. Being in command, O'Neill has been blamed for complicity or lack of oversight in these
massacres, the detail of which is still a matter of contentious debate. On 24 October 1641 O'Neill issued the
Proclamation of Dungannon in which he claimed to have the King's authorisation to rise in defence of the Crown and the Catholic religion. On 4 November 1641 O'Neill repeated these claims in his proclamation alongside
Rory Maguire at
Newry and read out a commission from
Charles I of England dated 1 October, commanding him to seize: "... all the forts, castles, and places, of strength and defence within the
kingdom, except the places, persons, and estates of Our loyal and loving subjects the Scots; also to arrest and seize the goods, estates, and persons of all the English Protestants, within the said kingdom to Our use. And in your care and speedy performance of this Our will and pleasure We shall rely on your wonted duty and allegiance to Us which We shall accept and reward in due time." This gave O'Neill's forces the impression that they were acting within the law. Charles later denied having issued the commission. In November O'Neill attacked
Lisburn several times but failed to take it. Like other rebel leaders, O'Neill had difficulty with the discipline of his troops, which was compounded by his comparative lack of social status. In an effort to improve this O'Neill planned to have himself declared
Earl of Tyrone at the historic site of
Tullyhogue. Nalson, in his "History of the General Rebellion in Ireland", described O'Neill as: "Sir Phelemy Roe O Neill, captain-generall of all the rebels, and chieftain of the O Neills, O Hagans, O Quyns, O Mellans, O Hanlons, O Corrs, McCans, McCawells, Mac Enallyes, O Gormelys, and the rest of the Irish septs in the counties of Tyrone and Ardmagh." == Confederate ==