Marquess of Hertford

The titles of Earl of Hertford and Marquess of Hertford have been created several times in the peerages of England and Great Britain.

The third Earldom of Hertford was created in 1559 for Edward Seymour, who was simultaneously created Baron Beauchamp of Hache. His grandson William Seymour was subsequently created Marquess of Hertford and restored to the title of Duke of Somerset; the Marquessate became extinct in 1675 and the other three titles in 1750.

The present Marquessate was created in 1793. Lord Hertford holds the subsidiary titles of Earl of Yarmouth (Peerage of Great Britain, 1793), Earl of Hertford (Peerage of Great Britain, 1750), Viscount Beauchamp (Peerage of Great Britain, 1750), Baron Conway, of Ragley in the County of Warwick (Peerage of England, 1703), and Baron Conway of Killultagh, of Killultagh in the County of Antrim (Peerage of Ireland, 1712). Lord Hertford's heir uses the style Earl of Yarmouth.

The Marquesses of Hertford are members of the Seymour family headed by the Duke of Somerset. Francis Seymour (1679–1732) was the fourth son of Sir Edward Seymour of Berry Pomeroy, 4th Baronet, a descendant of Edward Seymour, 1st Duke of Somerset (Sir Edward's grandson Sir Edward Seymour, 6th Baronet, of Berry Pomeroy succeeded as 8th Duke of Somerset in 1750). Upon the death of his elder brother, Francis succeeded to the estates of his relative Edward Conway, 1st Earl of Conway. In 1703 he was created Baron Conway in the Peerage of England and assumed the additional surname of Conway. In 1712 he was created Baron Conway of Killultagh in the Peerage of Ireland. In 1750 his son Francis Seymour-Conway, 2nd Baron Conway, was created Viscount Beauchamp and Earl of Hertford. These were revivals of titles previously held by the Dukes of Somerset, which had become extinct the same year on the death of Seymour-Conway's kinsman Algernon Seymour, 7th Duke of Somerset. In 1793 he was further honoured when he was made Earl of Yarmouth and Marquess of Hertford. The latter title had also previously been held by the Dukes of Somerset, but had become extinct in 1675 (see below). As a descendant of Edward Seymour, 1st Duke of Somerset, the present Marquess of Hertford is in remainder to the Dukedom of Somerset and its subsidiary title the Barony of Seymour.

The family seat is Ragley Hall, near Alcester, Warwickshire.

Earls of Hertford, First creation (1138)

 * Richard Fitz Gilbert de Clare (d. 1136), traditionally but erroneously called Earl of Hertford
 * Gilbert de Clare, 1st Earl of Hertford (d. 1153)
 * Roger de Clare, 2nd Earl of Hertford (d. 1173)
 * Richard de Clare, 3rd Earl of Hertford (d. 1217)
 * Gilbert de Clare, 4th Earl of Hertford (d. 1230) became Earl of Gloucester in 1218
 * For further Earls, see Earl of Gloucester.

Earls of Hertford, Second creation (1537)

 * Edward Seymour, 1st Duke of Somerset, 1st Earl of Hertford (1506–1552), forfeit 1552

Earls of Hertford, Third creation (1559)

 * Edward Seymour, 1st Earl of Hertford (1539–1621)
 * William Seymour, 2nd Earl of Hertford (1587–1660) (became Marquess of Hertford in 1641)

Marquesses of Hertford, First creation (1641)

 * William Seymour, 2nd Duke of Somerset, 1st Marquess of Hertford (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) (Marquessate extinct 1675)

Earls of Hertford, Third creation (1559; Reverted)

 * Francis Seymour, 5th Duke of Somerset (1658–1678)
 * Charles Seymour, 6th Duke of Somerset (1662–1748)
 * Algernon Seymour, 7th Duke of Somerset (1684–1750) (Earldom extinct on his death in 1750)

Barons Conway, Second creation (1703)

 * Francis Seymour-Conway, 1st Baron Conway (1679–1732)
 * Francis Seymour-Conway, 2nd Baron Conway, (1718–1794) (created Earl of Hertford in 1750 and Marquess of Hertford in 1793)

Earls of Hertford, Fourth creation (1750)

 * Francis Seymour-Conway, 1st Earl of Hertford, (1718–1794) (created Marquess of Hertford in 1793)

Marquesses of Hertford, Second creation (1793)
The heir apparent is the present holder's eldest son, William Francis Seymour, Earl of Yarmouth (b. 1993).
 * Francis Seymour-Conway, 1st Marquess of Hertford (1718–1794)
 * Francis Ingram-Seymour-Conway, 2nd Marquess of Hertford (1743–1822)
 * Francis Charles Seymour-Conway, 3rd Marquess of Hertford (1777–1842)
 * Richard Seymour-Conway, 4th Marquess of Hertford (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)

Line of succession

 * 1) William Francis Seymour, Earl of Yarmouth (b. 1993), eldest son of the 9th Marquess
 * 2) Lord Edward George Seymour (b. 1995), second and youngest son of the 9th Marquess
 * 3) A/Cdre. Andrew Conway Paul Seymour (b. 1939), grandson of Commander Lord George Frederick Seymour, fourth and youngest son of the 6th Marquess
 * 4) Nicholas George Mark Seymour (b. 1953), first cousin of A/Cdre. Andrew Seymour
 * 5) William Thomas Seymour (b. 1954), great-grandson of Rev. Lord Victor Alexander Seymour, fourth and youngest son of the 5th Marquess
 * 6) Conway William Hugh Seymour (b. 1934), first cousin once removed of William Thomas Seymour
 * 7) Conway Ronald Hugh Seymour (b. 1962), only son of Conway William Hugh Seymour
 * 8) Hugh James Seymour (b. 1956), great-great-great-great-grandson of Admiral Lord Hugh Seymour, fifth son of the 1st Marquess
 * 9) Hugo Frederick James Seymour (b. 1988), eldest son of Hugh James Seymour
 * 10) Rupert Alexander Erskine Seymour (b. 1992), second son of Hugh James Seymour
 * 11) Felix Horatio Hindmarch Seymour (b. 2000), third son of Hugh James Seymour
 * 12) Otto Storm Hindmarch Seymour (b. 2003), fourth and youngest son of Hugh James Seymour
 * 13) Julian Seymour (b. 1961), younger brother of Hugh James Seymour
 * 14) Francis Benedict Seymour (b. 1966), younger brother of Hugh James and Julian Seymour
 * 15) Thaddeus Oliver Thomas (b. 2001), eldest son of Francis Benedict Seymour
 * 16) Noah Benedict Hugh (b. 2003), second and youngest son of Francis Benedict Seymour
 * 17) Hugh Leopold Seymour (b. 1943), great-great-great-grandson of Lord George Seymour, seventh and youngest son of the 1st Marquess
 * 18) Charles Richard Seymour (b. 1955), younger brother of Hugh Leopold Seymour
 * 19) Rafe Conway Seymour (b. 1994), eldest son of Charles Richard Seymour
 * 20) Leo Miles Seymour (b. 1997), second and youngest son of Charles Richard Seymour
 * 21) Thomas Oliver Seymour (b. 1952), first cousin of Hugh Leopold and Charles Richard Seymour
 * 22) Edward Alexander Seymour (b. 1992), eldest son of Thomas Seymour
 * 23) William Seymour (b. 1994), second and youngest son of Thomas Seymour
 * 24) Lt.-Col. Conway John Edward Seymour (b. 1941), second cousin of Hugh Leopold, Charles Richard and Thomas Seymour
 * 25) Harry Edward Seymour (b. 1971), only son of Lt.-Col. Conway Seymour
 * 26) Richard Hubert Seymour (b. 1947), younger brother of Lt.-Col. Conway Seymour
 * 27) James Richard Edward Seymour (b. 1985), only son of Richard Seymour
 * 28) Julian Conway Seymour (b. 1934), first cousin once removed of Hugh Leopold, Charles Richard, Thomas, Lt.-Col. Conway and Richard Seymour
 * 29) Leopold Conway Seymour (b. 1959), eldest son of Julian Conway Seymour
 * 30) Frederick Conway Seymour (b. 2000), eldest son of Leopold Seymour
 * 31) William Titus Beauchamp Seymour (b. 2002), second and youngest son of Leopold Seymour
 * 32) Mark Hamilton Seymour (b. 1960), second son of Julian Conway Seymour
 * 33) Archibald John Seymour (b. 1937), second cousin once removed of Julian Conway Seymour and third cousin of Hugh Leopold, Charles Richard, Thomas, Lt.-Col. Conway and Richard Seymour
 * 34) Julian Roger Seymour (b. 1945), younger brother of Archibald Seymour
 * 35) Archie Christopher Seymour (b. 1989), only son of Julian Roger Seymour
 * 36) Christopher Mark Seymour (b. 1942), first cousin of Archibald and Julian Roger Seymour
 * 37) Thomas Mark Middleton Seymour (b. 1972), eldest son of Christopher Seymour
 * 38) Peter Christopher James Seymour (b. 1977), second and youngest son of Christopher Seymour