[8][9][10] His father was Brian O'Connor Faly, Baron Offaly,[11] and his mother was Lady Mary FitzGerald, daughter of the 9th Earl of Kildare.
In 1560, he accompanied representative Henri Cleutin to France, and appealed to Catholic Englishman Francis Throckmorton to "intercede for his pardon and restoration".
[4] In response to the Massacre of Mullaghmast led by Francis Cosby and Lord Deputy Henry Sidney, where over 100 Gaelic nobles were killed, the enraged O'Connor Faly "inflicted great devastation on the English, and often vainly attacked them".
Lord Deputy Arthur Grey ordered Henry Warren, sheriff of King's County, to call for Mackworth's release.
The men pried his jaws open with their hands, and upon reading the parchment, O'Connor Faly discovered it was an order from the Queen for Mackworth to capture and kill him.
The rebel and his followers dispersed themselves among the wilderness of Kildare to escape Grey's incoming forces; they planned to remain hidden until winter for a better chance of retaliation.
[2] O'Connor Faly subsequently fled to Scotland in a pinnace; then, disguised as a sailor, he stowed away on a Scottish vessel to Spain.
[6][1] During this time he regularly corresponded with Hugh O'Neill, Earl of Tyrone, leader of the Irish confederacy during the Nine Years' War.
[7] In January 1596, the English Crown received a report that 17 ships were set to take 12,000 Spanish soldiers through St George's Channel to Lambay Island, Ireland.
[6] In late October 1596,[18][19] O'Connor Faly embarked the 2nd Spanish Armada at Lisbon with his mother, wife, and children, attempting to sail back to Ireland.