He married, on 27 Jan. 1635, Isabella, youngest daughter and coheiress of Sir Nicholas Saunders of Ewell in Surrey; she died, aged 52, on 11 March 1656–7, and was buried in East Peckham church on 17 March (her holograph ‘Diary,’ 1645–51, comprises Addit. MSS. 34169–72). Sir Roger gives an affecting picture of her last hours, and sums up: ‘She was the saver of my estate. Never man had a better wife, never children a better mother.’ They had issue (1) Sir William, third baronet (d. 27 Nov. 1697), grandfather of Philip Twysden, bishop of Raphoe (from 1747 until his death on 2 Nov. 1752), whose daughter Frances married in 1770 the fourth Earl of Jersey, and as ‘Lady Jersey’ is conspicuous in ‘Walpole's Correspondence;’ (2) Roger, who died without issue in 1676; (3) Charles, a traveller in the east, who died in 1690; and three daughters: Anne, who married John Porter of Lamberhurst, Kent; Isabella (d. 1726); and Frances, who married Sir Peter Killigrew of Arnewick, and died in 1711.
Twysden had a knowledge of and affection for the usages and liberties of his country scarcely, if at all, exceeded in an age which comprehended the great names of Coke, Selden, Somner, Spelman, Evelyn, Cotton, and Savile. Like Selden, and like his early friend D'Ewes, amid all the distraction of political life and public duties as a magistrate and county magnate, he devoted the best energies of a powerful mind to the investigation of historical antiquity. Unlike them, as we learn from Kemble—who thoroughly explored his literary remains—his published works give only a slight notion of the resources of his well-stored mind or the energy of his application. To form an adequate conception of these one should have studied his numerous commonplace books, his marginal notes, his interleaved copies, and the treatises by him still awaiting a competent editor. Beneath these acquirements is discernible a character remarkable for steadfastness, piety, and true manliness. ‘Loyal, yet not a thorough partisan of the king; liberal, yet not proposing to go all lengths with the parliament; an earnest lover of the church of England, yet anxious for a reconciliation with Rome could such be effected without the compromise of any point of bible Christianity; a careful manager, yet an indulgent landlord; a somewhat stern and humorous man, yet a devoted son and husband and an affectionate father—such is the picture of a man who even to this day excites in us feelings of respect and attachment’ (Kemble).
The three of his works that were printed and published in Twysden's lifetime are: 1. ‘The Commoners Liberty: or the Englishman's Birth-right,’ London, 1648, proving from Magna Carta the illegality of his arrest and imprisonment. 2. ‘Historiæ Anglicanæ Scriptores Decem: Simeon Monachus Dunelmensis, Johannes Prior Hagustaldensis, Ricardus Prior Hagustaldensis, Ailredus Abbas Rievallensis, Radulphus de Diceto Londoniensis, Johannes Brompton Jornallensis, Gervasius Monachus Dorobornensis, Thomas Stubbs Dominicanus, Gulielmus Thorn Cantuariensis, Henricus Knighton Leicestrensis, ex vetustis manuscriptis nunc primum in lucem editi. Adjectis variis lectionibus Glossario indiceque copioso .... sumptibus Cornelii Bee,’ London, 1652, folio. The introduction ‘Lectori’ is signed Roger Twysden, and dated ‘ex ædibus meis Cantianis.’ Three of these chronicles, those of Simeon of Durham [1882], Henry Knighton [1889], and Ralph of Diceto [1876], have since been edited separately in the Rolls Series, the editors in each case speaking of Twysden's work with respect. The last-mentioned work, drawn in the main from the royal manuscript in the king's library at St. James's, was carefully collated with a copy of the Lambeth manuscript (the codex A of the Rolls version). The work entitles Twysden to rank along with Camden, Selden, Savile, and Kennet as a pioneer in the study of English mediæval history. ‘Even the Puritans themselves,’ says Hearne, ‘affecting to be Mæcenases with Cromwell at their head, displayed something like a patriotic ardour in purchasing copies of this work as soon as it appeared’ (pref. to his edition of Otterbourne; cf. Dibdin, Libr. Comp. pp. 161–2). 3. ‘An Historical Vindication of the Church of England in point of Schism as it stands separated from the Roman and was Reformed 1° Elizabeth.’ The address ‘To the Reader’ is ‘given from my house in East Peckham on 22 May 1657,’ and the work appeared in July (London, 8vo; 2nd edit. 1675; Pitt Press, 1847, with additional matter, and embodying the author's latest marginalia and notes). In this work Twysden gives a most able expository sketch of early resistance to Romish authority from the time of Wilfrid's appeal, of the gradual encroachments of the papal power, and ‘how the kings of England proceeded in their separation from Rome.’
In addition to these separate printed works Twysden aided in the production of the Cambridge edition in 1644 of ‘Archaiomena, sive De Priscis Anglorum legibus libri,’ prefixing to the supplement, ‘Leges Willielmi Conquestoris et Henrici filii ejus,’ a Latin
