His maternal grandparents were Robert Rochfort of Kilbryde, County Meath and Elinor Dillon (a daughter of Sir Lucas Dillon, Chief Baron of the Exchequer of Ireland).[3] His paternal grandparents were Margaret (née Forster) Dongan and John Dongan, originally of Fishamble Street, Dublin, a civil servant in the Irish Government who became wealthy and acquired substantial estates in County Kildare.[4]
Upon his father's death in 1626, he became the 2nd Baronet and took up residence at Castletown.[1] He was a member of the Irish Parliament of 1634, under King Charles I of England. In 1643, he was a captain of horse.[2]
Dongan was married to Mary Talbot, one of eight sons and eight daughters of Sir William Talbot, 1st Baronet and the former Alison Netterville.[5] Together, they were the parents of at least ten children, including:[2]
William Dongan, 1st Earl of Limerick (c. 1630–1698), the 4th Baronet who was made Viscount Dungan, of Clane in the County of Kildare in 1661 and Earl of Limerick in 1686, with remainder, failing male issue of his own, to his brothers Robert, Michael and Thomas and the heirs male of their bodies. [6]
Through his daughter Margaret, he was the grandfather of Mary Barnewell, who married her cousin, Michael Nugent, and were the parents of Robert Nugent, 1st Earl Nugent.[8][9]
^Dungan, T. P. John Dongan of Dublin, an Elizabethan Gentleman (1988) The Journal of the Royal Socirty of Antiquaries in Ireland Vol, 118 p.101
^Cokayne, G. E., ed. (1893). Complete Peerage of England, Scotland, Ireland, Great Britain and the United Kingdom, extant, extinct, or dormant (L to M). Vol. 5 (1st ed.). London: George Bell & Sons. p. 82, line 5: "Thomas (Dongan) EARL OF LIMERICK &c. [I.], yr. br. of the above earl. and on whom this Earldom and the Viscountcy of Dongan of Clane were entailed under the spec. rem. in their respective creations, was b. 1654 and appears, notwithstanding the attainder of 1691, to have assumed in 1698 and been generally allowed the peerage [I.]."{{cite book}}: CS1 maint: postscript (link)