George Shiffner who married Mary, the Bridger heiress, came of a merchant family. His grandfather, Matthew, was a Russian subject who became a naturalized Englishman in 1711 under the Act 7 Anne, c.5 (1708), and is described as 'an Antient Member of the Russia Company in England'; he took up residence in London. (See Nos. SHR/1734-1737) Matthew's father was reputedly an Archbishop of Riga, (See No. SHR/5. Matthew married Agnata Brewer, said to be gouvernante to the Duchess of Courland, who later became Empress Ann of Russia, 1730-1740 (not Elizabeth, as stated in some papers in No. SHR/5). The Empress was godmother to Matthew's daughter Benigna.) but no such dignity seems to have ever existed. Matthew refers to five of his six children in his will proved in 1756, (No. SHR/439) and it appears that his sons Henry and John carried on his trade as merchants in Broad Street, London, principally with Northern Europe, (See Nos. SHR/2765-2812) and we have some accounts and papers relating to their insolvency in 1761 which Henry, in a letter to the Duke of Newcastle, (No. SHR/1738) ascribed to his brother's foolishness. It was an unfortunate event because Henry has just been elected Member of Parliament for Minehead, Somerset. John married Elizabeth Eleanor, daughter of Stephen Peter Godin (For his children and descendants, see his Family Note Book, transcribed in The Genealogist, vol. 28, pp. 129-141) who was a trustee to the Shiffners. Samuel and Matthew Shiffner (the other two sons) both died without heirs overseas, (According to a note by Sir George Shiffner, 1st bart., in No. SHR/5.) the one in Jamaica and the other at Hernont. One daughter, Catherine, married Matthew Dorrien, a London merchant, to whom some papers relate (Nos. SHR/641-655); their daughter Agnata married William Bingham, D.D. The other Shiffner daughter, Benigna, married Vincent John Biscoe of Hookwood, Surrey, and their daughter, Agnata Frances, married Sir William Ramsay of Bamff, 7th bart.
Henry Shiffner first married Ann Bronsdon of Blackheath, Kent, in 1749. (No. SH340 is a settlement dated 9 August 1749. In March 1757/8 he was accounting for 'Contingencies under the Wills of Thomas, Peter & Mary Bronsdon, & of My Late Wife' (see No. SHR/1739, fo. 5, where there is an account for the maintenance of Mary Bronsdon until her death in 1778).) She must have died soon after, for ten years later (Settlement, 8 March 1759 (see SHR/340-370).) he married Mary, daughter of John Jackson, governor-elect of Bengal. She brought the Pontrilas estate in Kentchurch, Ewyas Harold, Kenderchurch and Rowlestone in Herefordshire to the Shiffners and Henry lived there; two good views (Nos. SHR/3307, 3308 (see p. 73).) of the house date from this period. The estate was finally sold to a Dr. Trenchard in 1810. (No. SHR/2573) Of Henry's six children only two survived infancy: Thomas, who died in 1800, and George who married Mary Bridger.
George settled down to the life of a country gentleman having before marriage spent five years in the 11th regiment of Light Dragoons as a cornet. (Army List. His appointment dated 27 February 1782; for his resignation see No. SHR/3035) He then took an active part in local affairs as a justice of the peace, (He took his oath of qualification at the Epiphany sessions, 1803; East Sussex Record Office, QO/EW35.) deputy lieutenant (For his commission, 25 August 1798, see No. SHR/141.) and as Captain of the Lewes Troop of Yeomanry and Captain of the South Lewes Volunteer Battalion during the Revolutionary and Napoleonic Wars. (See Nos. SHR/90-139, 327.) He took over his father-in-law's work in connection with the joint estates in England and America and continued to improve and extend the Coombe estate. We have ample evidence of these activities in his correspondence and diaries, the latter being continuous from 1784 to 1837. His local reputation was such that he was considered as a candidate for Sussex in the Conservative interest in the 1807 parliamentary election in the place of the sitting Member, John Fuller, who had become unpopular for his outspoken defence of slavery in the colonies. This was a delicate matter since Shiffner had proposed him in 1801 and was related to him, but as Fuller persisted in his candidature, Shiffner declined the invitation; (See Nos. SHR/145-169, and T. W. Horsfield, The History, Antiquities and Topography of the County of Sussex, vol. 2 (1835), Appendix, p. 25.) instead, he sat for Lewes from 1812 to 1826. (Horsfield, op. cit., Appendix, pp. 47-49.) He had a baronetcy conferred on him in 1818.
Of George Shiffner's children, two served with distinction in the Armed Forces. His eldest son, John Bridger Shiffner, entered the 3rd Regiment of Foot Guards in 1805 and became lieutenant by seniority in 1811. He was on active service in the Spanish Peninsula from 1809 until his untimely death--after the war had officially ended--in the sortie from Bayonne in 1814. (Army Lists. His commissions were dated 24 October 1805 and 27 March 1811 respectively. The list does not distinguish lieutenants from captains in the regiment.) The greater part of the 191 letters to his father were written when on service and provide a valuable first-hand account of conditions and life there. (Nos. SHR/1037-1228.)
The death of this eldest son caused George to recall his second son, Henry, from his Indian station in the Navy. Henry had an active and successful naval career which is conveniently described in W. R. O'Byrne, Naval Biographical Dictionary (1849):--
This officer entered the Royal Navy Academy in May 1802; and embarked in Dec. 1805, as Fst.-cl. Vol., on board the Thetis 38, Capts. Wm. Hall Gage and Geo Miller, under whom he was for three years employed in the North Sea, off the coasts of France, Spain and Portugal, in the Mediterranean, and at St. Helena. Soon after he had joined the Thisbe 28, flag-ship of Sir Henry Edwin Stanhope at Deptford, he was made Lieutenant, 10 Feb. 1809, in the Trusty 50, Capt. Brain Hodgson. In the following March he removed to the Owen Glendower 36, (In this ship he assisted at the capture of the island of Anholdt 18 May 1809.) Capts. Wm. Selby, Edw. Henry A'Court, and B. Hodgson; and after serving for three years and seven months in that ship on the Baltic, Channel, North American, Mediterranean, Cape of Good Hope and East India Stations, he received, in Oct. 1814, a Commander's Commission, dated 22 of the preceding Feb., appointing him to the Sphynx sloop, building at Bombay. Returning to England on Admiralty leave in 1815, he next, 6 Jan. 1818, and 1 July 1819, obtained command of the Drake 10 and Carnation 18, both on the Newfoundland station; where he was nominated, 11 Sept. in the latter year, Acting-Captain of the Egeria 26. In that ship, to which he was confirmed 10 Nov. following, he remained until paid off 5 Jan. 1820. His last appointment was, 7 April 1834, to the Hastings 74, bearing the flag of Sir William Hall Gage at Lisbon. He was placed on half-pay 12 Jan. 1838; and on 1 Oct. 1846 he accepted the Retirement.
After accepting retirement in 1846, he was promoted in the retired list according to custom, to rear-admiral on 19 January 1852, and vice-admiral 10 September 1857. (Navy Lists.) A large number of administrative papers surviving from his last command might have been expected to be in official custody. (Nos. SHR/193-270.) At home, he was a justice of the peace, and became chairman of Quarter Sessions. (He was placed on the commission in 1817 and is addressed as chairman in 1853; see Nos. SHR/271-281.) He succeeded to the baronetcy on his father's death in 1842, which passed, on his own death, in 1859, without issue, to his brother George.
Sir George Shiffner, 3rd bart., the first baronet's third son, went to Christ Church, Oxford, as did his maternal grandfather; he matriculated in 1810, (J. Foster, Alumni Oxonienses. George Croxton Shiffner also went to Christ Church, Oxford, and matriculated 17 October 1838, aged 19.) aged 19, and later took holy orders. He was rector of St. Ann Lewes and of Hamsey, 1814-1848, when he resigned both, the latter in favour of his son George Croxton Shiffner. Sir George was prebendary of Eartham in Chichester cathedral and in 1848 until his death in 1863 he was vicar of Amport, Hampshire, a living in the gift of the Dean and Chapter of Chichester. (See Nos. SHR/2935-2946, and Diocesan Record Office, Chichester, CAP. I/3/6.) Thomas, the fourth son, matriculated at Christ Church Oxford in 1815; he studied law at Lincoln's Inn in 1819, and became paymaster of the Queen's Household. (J. Foster, Alumni Oxonienses.) He purchased the Westergate House estate, Aldingbourne, in 1846. (See Nos. SHR/396-437.)
Three of the Rev. Sir George Shiffner's sons entered the army, but only John, who fell in an attack on the Redan redoubt at the seige of Sebastopol on 18 June 1855, has left his mark. Having been first commissioned in the 53rd regiment of Foot, 15 October 1841, he became Captain in the 34th regiment of Foot, 3 August 1849, with whom he served in the Crimea. A faded photograph (In No. SHR/1330.) of him taken on the campaign shows him bearded, smoking a cigar, and in the rough dress of a hardened campaigner.
Details of later members of the family are given in Burke's Peerage and Baronetage.

Source  http://www.nationalarchives.gov.uk/a2a/records.aspx?cat=179-shiffner&cid=0#0