Previously for airing his views James had earned a night in jail, a sermon, a fine and the lasting enmity of Adam Loftus, the Protestant Archbishop of Dublin.
James had as his tutor an influential priest, Sir Norman Eustace and became a fervent Catholic who regarded Queen Elizabeth I as illegitimate, a usurper, a tyrant, and a heretic.
Mary died in 1610, having married secondly, in 1587, Sir Gerald Aylmer, Bart., of Donadea, a Catholic loyalist, repeatedly imprisoned, but finally released and knighted, by Elizabeth I and created baronet by James I of England.
He married Genet Preston, and during the period 1545 to 1551 received many grants of land, including Rathmore and part of Haynestown (east of Naas), Tomogue, and estates in County Carlow.
In 1576, before the death of his father, James Eustace lodged complaints against the religious persecution of the Catholic Church in Ireland and the illegal taxation ordered by the Lord Deputy, Sir Henry Sidney.
The persecution was further escalated in retaliation for Pope Pius V's excommunication of Queen Elizabeth in the 1570 Papal bull Regnans in Excelsis.
During the summer of 1580, James Eustace, Viscount Baltinglass, apparently prompted almost entirely by religious motives, recruited a Catholic army in County Wicklow, with the goal to assist Desmond.
James Eustace knew that he lacked the necessary military muscle, a suitable operational base and martial experience to be successful.
At first, the revolt was successful, and on 25 August 1580, a severe defeat was inflicted upon the troops of the Lord Deputy in the Wicklow Mountains at the Battle of Glenmalure.
The Annals of the Four Masters states that "the entire extent of country from the Slaney to the Shannon and from the Boyne to the meeting of the Three Waters became one scene of strife and dissension".
A force of Spaniards and Italians had landed at Smerwick, County Kerry, in order to assist the Catholic cause, but when they had completed the long march of 150 miles to Naas were taken prisoner and massacred.
He was well received, and only just failed to persuade King Philip II of Spain to provide sufficient troops and ships to invade Ireland.
Under this Act, the Eustace family, it's titles and arms were attainted, and all the vast Baltinglass possessions were forfeited, with retrospective clauses voiding all transfers of property that had taken place during the previous twelve years.
Lord James and his brothers had fought what they considered a just war, but they had been defeated and, for their failure, both their family and the Catholic Church in Ireland paid dearly.
Whether James Eustace and his followers were traitors or national heroes who died fighting to save their country from what would become centuries of religious persecution, they were certainly brave men.
At the time of the attainder, the Dowager Viscountess, once a proud Butler, but now the mother of "the six traitorous brethren," petitioned (rather pathetically, and with what result we can well imagine) to be allowed to retain her jointure or alternatively to be granted somewhere else to live.
The title was revived in 1685, when Colonel Richard Talbot, of Carton, was created Viscount Baltinglass, but he died without an heir six years later.