Sir Nathaniel Catelyn (c. 1580 – 1637) (whose family name is also spelt Catlyn or Catlin), was a leading English-born politician and judge in seventeenth-century Ireland.
Despite accusations of conflict of interest and of Roman Catholic sympathies, he retained the confidence of the Crown and was a key ally of Thomas Wentworth, 1st Earl of Strafford, the Lord Deputy of Ireland.
He was born in Suffolk, younger son of Richard Catlin III (1547 - 1596) of Woolverstone Hall, near Ipswich, and his wife, Dionysia, daughter of Thomas Marsh, Clerk of the Court of Star Chamber.
[5] On the other hand, James Butler, 1st Duke of Ormonde (who was only a teenager at the time), said many years later that as he remembered the office had been created simply as a favour to Catlin; in his view, the position of Second Serjeant was "wholly useless to the King and little profitable to anyone".
In 1629, the Crown, having for some years tolerated the open celebration of the Roman Catholic faith in Dublin, decided on vigorous enforcement of the Penal Laws.
On 26 December news came that troops were being sent into the city to prevent the celebration of the Mass; a serious riot developed and a large mob stoned the Anglican Archbishop of Dublin, Lancelot Bulkeley, who had to take refuge in a private house for his own safety.
[8] Charles I would not tolerate the questioning of his royal prerogative by one of his own law officers, and ordered "the man Catlin's" dismissal from as position of Recorder on the ground that he was a ringleader of the trouble.
A key part of Strafford's programme was to demonstrate the Crown's ability to manage the Irish Parliament, and for this purpose a compliant Speaker was essential.
Strafford dealt with this problem in a typically ruthless fashion by summoning the Sheriff of Dublin City, Christopher Brice, who had returned the "wrong" candidate, before the Court of Castle Chamber, fining him heavily and barring him from office for life.