Born: 02 July 1594, Meanus, County Kerry
Entered: 26 December 1622, Villagarcía, Galicia, Spain - Castellanae Province (CAST)
Ordained: c 1622, Salamanca, Spain - pre Entry
Final Vows: 05 August 1639
Died; 22 February 1684, Royal College, Salamanca, Spain - Castellanae Province (CAST)

Son of Arnissius O’Sullivan and Cecilia Carty

1625 Minister of Irish College Salamanca Age 33 - 1626 given as in Spain
1628 at Oviedo College, Minister Age 32. Has talent and mature judgement
1633 Came to Mission was Rector of Compostella
1637 ROM Catalogue “because he has always been alone, Informationes cannot be had
1649 At Waterford (55 after name)
1655-1684 Irish College of Salamnca. Confessor, was Superior of the College (1669-1675). Is very proficient in letters. Age 61 Soc 37
Is this the one of whom and English spy wrote “There is one Sir Teage O’Sullyvan...an earnest preacher of Popery...in Waterford” and “James Sherlock doth reteyne in his house one Doctor Teige O’Swillivan, a Jesuyt Semynary” (Kilkenny Arch Journal Vol I Part I pp82-83

◆ Fr Edmund Hogan SJ “Catalogica Chronologica” :
He was of the O’Sullivan Mór or the O’Sullivabn Beare Clan. He was a cousin of Count (Conde de) Berehaven
Studied Theology for four years in the Society, and knew Irish, English, Spanish and Latin
Was Rector at Compostella
1633 Sent to Irish Mission and became a Superior of Limerick Residence for five years (1646).
Mercure Verdier in his 1649 Report to the General on the Irish Mission found Thady at Waterford aged c 55, and reports him as eminent for virtue. learning and nobility. He possessed talents for business and public oratory, was a descendant of the ancient Irish, had few equals and ought to be promoted to the office of Superior of the Irish Mission”. (cf Oliver, Stonyhurst MSS)

◆ Fr Francis Finegan SJ :
Son of Dermot and Cecilia née McCarthy
Had studied at Santiago and Salamanca where he was Ordained 1622 before Ent 26 December 1622 CAST
After First Vows he was sent for further studies to Santiago
1629 Rector of Irish College Santiago
1633 Sent to Ireland and initially was in Kerry, but was later sent to Limerick where he became Superior.
He was at Waterford when Mercure Versier came on his Visitation 1748-1749. In Verdier’s Report to the General he praised Thady's gifts of character and intellectual ability. He considered him well fitted to be Superior of the Mission.
At the Cromwellian conquest he went to England and worked among the Irish there. He was arrested and sentenced to death but his sentence was commuted to one of deportation.
He found refuge in CAST and spent many years as an Operarius at the Church attached to the Royal College Salamanca, where he died 22 February 1684.
After the Restoration the Irish Mission Superior tried to have him sent back.
He was a scion of the House of Bearhaven and the Earl of Bearhaven before his death appointed his Jesuit cousin executor of his will.

◆ George Oliver Towards Illustrating the Biography of the Scotch, English and Irish Members SJ
O’SULLIVAN, THADAEUS, Pere Verdier, so often mentioned, found this Professed Father at Waterford, and states that he was about 55 years of age. that he was eminent for virtue, learning, and nobility; that he possessed talents for business and Pulpit Oratory : that he was a descendant of the ancient Irish; that he had few equals; and that he ought to be promoted to the rank of Superior of his brethren, or Consultor of the Mission.