Sir John Seymour
- Sir John Seymour (1474–1536)
Children of Sir John Seymour and Margery Wentworth:
- Edward Seymour, 1st Duke of Somerset KG (c.1506-1552).
- Thomas Seymour, 1st Baron Seymour of Sudeley KG (c.1508-1549) married Catherine Parr ( c.1512 – 1548), Dowager Queen of England.
- Jane Seymour, Queen of England (c.1509-1537) Coat of Augmentation granted to her by Henry VIII and subsequently borne by all the Seymours of this line.
- Elizabeth Seymour, Marchioness of Winchester (c.1513-1563).
- Sir Henry Seymour (c.1514 - after 1568).
Viscount Beauchamp, ("of Hache") in the Peerage of England (1536–1552)
Barons Beauchamp ("of Hache") in the Peerage of England (1559–1750)
Earls of Hertford in the Peerage of England (1537,forfeit)
Dukes of Somerset in the Peerage of England (1547, forfeit 1552 to 1660)
Earls of Hertford in the Peerage of England (1559-1750)
Barons Beauchamp ("of Hache") in the Peerage of England (1559–1750)
Marquesses of Hertford in the Peerage of England (1641-1675)
1st Duke of Somerset KG
- Edward Seymour, 1st Viscount Beauchamp, 1st Duke of Somerset, 1st Earl of Hertford KG (1506–1552) Dukedom forfeited in 1552. Married firstly in 1527 (divorced 1535) Catherine Filliol, daughter and coheiress of Sir William Filliol of Filliol's Hall. Married secondly in 1537, Anne Stanhope (d. 1587) daughter of Sir Edward Stanhope, of Rampton by his wife Hon Elizabeth Bourchier, sister of John Bourchier, 1st Earl of Bath.
Viscountcy of Beauchamp created with remainder to the heirs male of his body hereafter to be begotten.
Earldom of Hertford created with remainder to his issue male already begotten or to be begotten of his then wife, or to be begotten of any subsequent wife.
Dukedom of Somerset and Barony of Seymour created with a special remainder to his issue male by his then wife, Anne, with remainder to Edward, his second son by his former wife, Katherine, and the heirs male of his body, and ultimate remainder to the heirs male of his own body by any subsequent wife.
The Dukedom of Somerset remained under attainder until 1660, when the title was restored to the 1st Duke's great-grandson, William Seymour, 2nd Earl of Hertford later 1st Marquess of Hertford later 2nd Duke of Somerset.
1st Earl of Hertford
- Edward Seymour, 1st Earl of Hertford, 1st Baron Beauchamp (1539–1621)
- Edward Seymour, Lord Beauchamp of Hache (1561–1612) married Lady Katherine Grey (d. 1568), the younger sister of Lady Jane Grey.
2nd Duke of Somerset KG
- William Seymour, 2nd Earl of Hertford, 2nd Duke of Somerset, 1st Marquess of Hertford KG (1587–1660) (restored to the Dukedom of Somerset in 1660)
- William Seymour, 3rd Duke of Somerset, 2nd Marquess of Hertford (1651–1671)
- John Seymour, 4th Duke of Somerset, 3rd Marquess of Hertford(d. 1675) on his death the Marquessate of Hertford became extinct.
Dukes of Somerset in the Peerage of England (1547, forfeit 1552 to 1660, from 1675-1750)
Earls of Hertford in the Peerage of England (1559-1750, from 1675-1750)
Barons Beauchamp ("of Hache") in the Peerage of England (1559–1750, from 1675-1750)
Barons Seymour of Trowbridge in the Peerage of England (1641-1750)
Earl of Northumberland in the Peerage of Great Britain (1749-1750)
Earl of Egremont in the Peerage of Great Britain (1749-1750)
Baron Percy in the Peerage of Great Britain (1722-1750), created by error
- Francis Seymour, 1st Baron Seymour of Trowbridge (c.1590–1664) younger son of Edward Seymour, Lord Beauchamp of Hache (1561–1612)
- Charles Seymour, 2nd Baron Seymour of Trowbridge (c.1621–1665)
- Francis Seymour, 5th Duke of Somerset, 3rd Baron Seymour of Trowbridge (1658–1678)
6th Duke of Somerset KG
6th Duke of Somerset KG (Marital arms)
- Charles Seymour, 6th Duke of Somerset KG (1662–1748) married Lady Elizabeth Percy (1667– 1722) only daughter and heir of Joceline Percy, 11th Earl of Northumberland.
7th Duke of Somerset
- Algernon Seymour, 7th Duke of Somerset, 1st Baron Percy, 1st Earl of Northumberland, Baron Warkworth, 1st Earl of Egremont, Baron Cockermouth (1684–1750)
Summoned as Baron Percy after the death of his mother (under the incorrect assumption that his mother had been possessed of the ancient Barony of Percy [cr. 1299] - this was in fact the creation of a new barony by writ)
Earldom of Northumberland and Barony of Warkworth of Warkworth Castle created with special remainder in default of male issue to his son-in-law Sir Hugh Smithson, 4th Bt. and the heirs male of his body by Lady Elizabeth Seymour, his wife, with remainder to the said Elizabeth and the heirs male of her body.
Earldom of Egremont and Barony of Cockermouth of Cockermouth Castle created with special remainder in default of male issue to his nephews, Sir Charles Wyndham, 4th Bt., and Percy O'Brien and their issue male successively.
On his death the Earldom of Hertford and the Baronies of Beauchamp and of Seymour of Trowbridge became extinct, the Barony of Percy passed to his daughter and the Baronies of Warkworth and of Cockermouth and the Earldoms of Northumberland and of Egremont passed according to their respective limitations.
- George Seymour, Viscount Beauchamp (1725–1744) only son of the 7th Duke, died without issue.
Seymour of Berry Pomeroy in the Baronetage of England (1611)
Dukes of Somerset in the Peerage of England (1547, forfeit 1552 to 1660, from 1750)
Earl St. Maur in the Peerage of the United Kingdom (1863-1891)
Seymour of Berry Pomeroy
- Sir Edward Seymour, 1st Baronet (c. 1563–1613) eldest grandson of (by his first marriage).
- Sir Edward Seymour, 2nd Baronet (c. 1580–1659)
- Sir Edward Seymour, 3rd Baronet (1610–1688)
- Sir Edward Seymour, 4th Baronet (1633–1708)
- Sir Edward Seymour, 5th Baronet (1663–1740)
Dukes of Somerset
- Sir Edward Seymour, 6th Baronet, 8th Duke of Somerset (1695–1757)
- Edward Seymour, 9th Duke of Somerset (1717–1792)
- Webb Seymour, 10th Duke of Somerset (1718–1793)
- Edward St Maur, 11th Duke of Somerset KG (1775–1855)
- Edward Seymour, 12th Duke of Somerset, 1st Earl St Maur KG (1804–1885)
- Ferdinand Seymour, Earl St Maur (1835–1869) eldest son of the 12th Duke, died without issue.
- Archibald Seymour, 13th Duke of Somerset (1810–1891)
- Algernon St Maur, 14th Duke of Somerset (1813–1894)
- Algernon Seymour, 15th Duke of Somerset (1846–1923)
- Duke of Somerset (1860–1931), descendant of the 8th Duke
- Evelyn Seymour, 17th Duke of Somerset (1882–1954)
- Percy Seymour, 18th Duke of Somerset (1910–1984)
- John Seymour, 19th Duke of Somerset (b. 1952)
Barons Conway in the Peerage of Great Britain (1703)
Barons Conway of Killultagh in the Peerage of Ireland (1712)
Earl of Hertford in the Peerage of Great Britain (1750)
Marquesses of Hertford in the Peerage of Great Britain (1793)
1st Baron Conway
- Francis Seymour-Conway, 1st Baron Conway (1679–1732) third son of Sir Edward Seymour of Berry Pomeroy, 4th Baronet. Francis succeeded to the estates of his mother’s relative Edward Conway, 1st Earl of Conway, and assumed the same year by Royal license the additional surname of Conway.
Marquesses of Hertford
- Francis Seymour-Conway, 1st Marquess of Hertford, Earl of Yarmouth, 1st Earl of Hertford and Viscount Beauchamp, 2nd Baron Conway KG (1718–1794)
- Francis Ingram-Seymour-Conway, 2nd Marquess of Hertford KG (1743–1822)
- Francis Charles Seymour-Conway, 3rd Marquess of Hertford KG (1777–1842)
- Richard Seymour-Conway, 4th Marquess of Hertford KG (1800–1870)
- Francis Hugh George Seymour, 5th Marquess of Hertford (1812–1884)
- Hugh de Grey Seymour, 6th Marquess of Hertford (1843–1912)
- George Francis Alexander Seymour, 7th Marquess of Hertford (1871–1940)
- Hugh Edward Conway Seymour, 8th Marquess of Hertford (1930–1997)
- Henry Jocelyn Seymour, 9th Marquess of Hertford (b. 1958)
Barons Alcester in the Peerage of the United Kingdom (1882-1895)
1st Baron Alcester
- Frederick Beauchamp Paget Seymour, 1st Baron Alcester (1821–1895), great-grandson of Francis Seymour-Conway, 1st Marquess of Hertford.
Seymour of Langley in the Baronetage of England (1681-1714)
Seymour of Langley
- Sir Henry Seymour, 1st Baronet (1674–1714) son of the second son of Sir Edward Seymour of Berry Pomeroy , 2nd Baronet.
Barons Conway in the Peerage of England (1624-1683)
Viscounts Conway in the Peerage of England ((1627-1683)
Viscounts Killultagh in the Peerage of Ireland (1627-1683)
Earl of Conway in the Peerage of England ( (1679-1683)
Earls of Conway
- Edward Conway, 1st Baron Conway, 1st Viscount Conway, 1st Viscount Killultagh (1564–1631)
- Edward Conway, 2nd Viscount Conway, 2nd Viscount Killultagh (1594–1655)
- Edward Conway, 1st Earl of Conway, 3rd Viscount Conway, 3rd Viscount Killultagh (1623–1683)