The following year the Earl of Kildare made a series of charges against the Earl of Ormond through Lord Leonard Grey, amongst which was that of keeping a ward of evil persons in Arklow Castle to rob the surrounding neighbourhood.
A few years later (1532) the Earl of Ossory and Ormond complained to Thomas Cromwell that the Earl of Kildare was trying to get some of his castles into his possession (amongst which he mentioned Arklow), under the plea of holding them by lease from the Earl of Wiltshire. He states these fortresses “bee the veray keyes of the cuntrey,” and that the King ought to prevent Kildare becoming too powerful. Sir Thomas Bullen had then been created Earl of Ormond and Wiltshire by Henry VIII.
During the rebellion of “the Silken Thomas” in 1536 the King had to send “an army royal” to get the castle of Arklow and others into his possession.
The following year the manor was re-granted to Peter Butler, Earl of Ossory and Ormond.
In 1578, when forming the county of “Wicklo or Arcklo,” the castle of the latter is mentioned as the chief place, and belonging to the Earl of Ormond, who was also Lord of Arklow.
The Lord Deputy placed a garrison there in 1581.
In March, 1589, Feagh M’Hugh O’Byrne seized the wife of Hugh Duff O’Donnell, uncle to Sir Hugh O’Donnell, who was a tenant of the Earl of Ormond in Arklow Castle. In the autumn of the same year O’Byrne tried to force an entrance into the castle “to execute his malice” upon Hugh O’Donnell.
The land was laid waste round the fortress in 1600, but the castle was held for the Queen by the Earl of Ormond at his own expense.
In the rebellion of 1641 the Irish surprised the fortress and killed the garrison. It remained in their possession until 1649, when it was captured by Cromwell’s forces, of which the following is the account:—
“The army marched through almost a desolate country until it came to a passage of the River Doro, about a mile above the Castle of Arklow, which was the first seat and honour of the Marquis of Ormond’s family, which he had strongly fortified; but it was upon the approach of the army quitted, wherein he (Cromwell) left another company of foot.”