HIS branch of the family sprung originally , it is supposed; from Sir Thomas Molineux, second son of Sir William Molyneux, of Sefton, Knight Banneret.

The immediate ancestor was Sir Thomas Molyneux, Knt., born in Calais in 1581, who was sent to Ireland by Queen Elizabeth in 1576 as Chancellor of the Exchequer, and received extensive grants of lands. He married Katherine, daughter of Ludovic Stabcort, Governor of Bruges, and died in 1596. His eldest surviving son, Daniel Molineux, of Newlands, Co. Dublin, born at Bruges, received in 1586 the appointment of Ulster King-at-Arms, and was M.P. for Strabane in 1613. By his wife, Jane, daughter of Sir William Ussher, Clerk of the Privy Council, he had five sons and three daughters. The eldest son, Thomas, Governor of Wicklow, was killed by the rebels in 1642. William, the second son, a barrister-at-law, was buried in Lincoln's Inn Chapel, where a small stone lies over his grave, inscribed “William Molyneux, Esq., 1651.“ Adam Molyneux, of Ballymulvey, Co. Longford, the fifth son, Provost Marshal of Leinster and M.P. for the county in 1660, was ancestor of the Barons Shuldham, his granddaughter, Elizabeth, daughter of Daniel Molyneux of Ballymulvey, having married the Rev. Lemuel Shuldham, of Dublin. Their eldest son, Lemuel, was ancestor of the Shuldhams of Ballymulvey and Moig House, Co. Longford. Molyneux, the second son, a Commodore in the Royal Navy, and Governor of the Island of Newfoundland in 1772, afterwards a Vice-Admiral, and M.P. for Fowey, was elevated to the peerage of Ireland, 31^st July, 1776, as Baron Shuldham. He married, 4^th October, 1790, Margaret Irene, daughter of John Sarney, but died without issue.

Samuel, eldest son of Sir Thomas Molineux, was constituted by letters patent from Queen Elizabeth, dated 21^st May, 1586, Marshal of the Court of the Castle Chamber, a Court of Judicature held in the Castle of Dublin, and in 1607 was appointed by King James I. Seneschal of the manor of Newcastle, Co. Dublin. He was M.P. for Mallow in 1613.

Samuel Molyneux, of Castle Dillon, Co. Armagh, the third but eldest surviving son of Daniel Molyneux, of Newlands, was Chief Engineer of Ireland, and married Anne, daughter and heiress of William Dowdall, of Mount Town, Co. Meath, by whom he had five sons and two daughters. William, the eldest surviving son, was M.P. for the City of Dublin in 1691, and for the University from 1694 until his decease. He was the author of the celebrated Case of Ireland. His wife was Lucy, daughter of Sir William Domville, Bart., Attorney-General for Ireland. His eldest son, the Right Hon. Samuel Molyneux, was Secretary to George II. when Prince of Wales; he subsequently became a Lord of the Admiralty, a Privy Councillor, and M.P. for Dublin University and the borough of Bossiney, England. He married in 1717 Lady Elizabeth Diana Capel, eldest daughter of Algernon, second Earl of Essex, but had no issue. The family estates reverted at the death of his widow in 1759, to his uncle, Thomas Molyneux, Professor of Physic in the University of Dublin, afterwards Physician-General to the army in Ireland, created a Baronet 4^th July, 1730, who married Catherine, daughter of Ralph Howard, of Shelton, grandfather of the first Lord Wicklow, by whom he had two sons, Daniel and Capel, and four daughters. Sir Daniel Molyneux , the eldest son, died unmarried in 1738, when the title and estates devolved upon his brother, The Right Hon. Sir Capel Molyneux, M.P. for the University of Dublin, who married, first, Elizabeth, daughter of William East, of Hall Place, Co. Berks, by whom he had issue three sons—Capel, George, M.P. for Granard, and William—and four daughters. Sir Capel married secondly Elizabeth, only daughter of Lieutenant-General Adlercron, by whom he had two sons, Thomas and John. He died in 1797, and was succeeded by his son Capel, fourth Baronet, who married in 1785 Margaret, eldest daughter of Sir Neil O'Donnel, Bart., of Newport, Co. Mayo, but died without issue in 1832, when the title devolved upon his brother, Sir Thomas Molyneux, Bart., a lieutenant-general in the army, who by his wife, Elizabeth, daughter of Thomas Perrin, had an only son and heir, George King Adlercron, who succeeded his father as sixth Baronet, and married Miss Emma Green, by whom he had issue two daughters and a son, Capel, who inherited the family honours and estates. He was a magistrate and deputy-lieutenant for the county of Armagh, and served as High Sheriff in 1867. He married in 1863 Mary Emily Frances, eldest daughter of Peter Fitzgerald, “Knight of Kerry,“ but died without issue in 1879, when the title passed to his father's cousin, the Rev. John William Henry Molyneux, Rector of St. Gregory's, Sudbury, Suffolk, and Honorary Canon of Ely, who was born in 1818, and married Louisa Dorothy, daughter of John Christian, Dempster of the Isle of Man. He died in March, 1879, a few weeks after his accession to the family honours, and was succeeded by his son, the Rev. Sir John Charles Molyneux, as ninth Baronet, born 27t^h June, 1843, and who married Fanny, daughter of Edward Jackson of Walsoken House, Wisbeach.

John, second son of Sir Capel Molyneux, fourth Baronet, married Miss Ella Young, and left issue four sons and seven daughters. The eldest son, Capel Molyneux, B.A., born 2^nd December, 1804, was Vicar of St. Paul's, Onslow Square, London, and married, 1^st June, 1831, Maria, second daughter of Admiral Carpenter, by whom, who died 15^th March, 1869, he had issue five daughters. Maria Jane, the eldest, married 17^th November, 1863, Lord William Pitt Lennox, fourth son of Charles, fourth Duke of Richmond, Governor-General of Canada, who died in 1819 from the effects of a bite from a rabid fox. The Rev. Capel Molyneux married secondly, 4^th October, 1870, Eugenia Grace, widow of Lieutenant-Colonel Alexander Murray.

The Castle Dillon estate was purchased in 1664 by Captain Samuel Molyneux. The park possesses all the requisites of sylvan beauty—wood, water, and variety of ground.

The family estates at the death of Sir Capel Molyneux, seventh Baronet, extended over 16,560 acres, of the estimated annual value of £10,000.

The Right Hon. Sir Capel Molyneux, M.P., third Baronet, erected an obelisk at Castle Dillon to commemorate the revival of the constitution of Ireland in 1782.

Sir Thomas Molineux, Chancellor of the Exchequer, resided in Thomas Court, near St. Catherine's Church, Dublin; he also rented from the then Archbishop the archiepiscopal country seat at Tallagh, near Dublin.