Matha Óg Ó Maoil Tuile (aka Matthew Tullie) was secretary to Rudhraighe Ó Domhnaill, 1st Earl of Tyrconnell and Hugh Ó Neill, 2nd Earl of Tyrone.
Ó Maoil Tuile is described as a learned man and a native of Connacht (2007, p. 429). He travelled to Spain with Hugh Roe Ó Donnell in 1602, receiving a pension of twenty-five crowns a month from Philip III of Spain. He was with Hugh Roe shortly before his death. Upon his return to Ireland he became secretary to Hugh Ó Neill, 2nd Earl of Tyrone. Via England, he returned to Spain in 1605.
He was instrumental in the departure of the Ulster lords - Ó Néill, Ó Domhnaill, Mag Uidir - arriving by ship at Rathmullen, county Donegal, on 4 September 1607. It was on this ship that the chiefs and their followers (a total of ninety-five people) left Ireland.
When the group reached Rouen, Ó Maoil Tuile travelled to Paris to appraise Henry IV of France of their arrival. Tadhg Ó Cianáin, a fellow-member of the group, wrote that:
He then travelled to Flanders where he contacted Ó Néill's son, Colonel Éinrí Ó Néill, telling him the group were going in that direction:
In Milan he composed a list of those of the party that remained in Flanders. He spent some years between 1608 and 1610 in the Spanish navy, but in the latter year was in Madrid.