- was created after the morganatic marriage of prince Alexander of Hesse by Rhine (1823 - 1888) and countess Julia Hauke (1825 - 1895). Officially Julia was the first "family member".
- Alexander's nephew Ludwig (Louis) (1837-1892) by his older brother Karl (Charles) succeed his childless uncle Grandduke Ludwig III (Louis III) as Ludwig IV (Louis IV) Grand duke of Hesse. Ludwig IV married princess Alice of the United Kingdom (1843-1878). In this line haemophilia was prominent (both sufferers and carriers). Ludwig IV and Alice had in total 7 children, of which the oldest child, Victoria, married her cousin once removed prince Louis of Battenberg (who in 1917 would become Mountbatten).
- Alexander and Julia had 5 children:1.
Marie (1852?1923), married in 1871 Gustav, Count of Erbach-Sch?nberg (d. 1908), with issue.2.
Ludwig (Louis) (1854-1921), who enrolled in the UK Royal Navy. He married his first cousin once removed, princess Victoria of Hesse by Rhine (1863-1950) (a granddaughter of Queen Victoria). Louis was created first Marquess of Milford Haven in 1917. In the same year he and his children gave up their German titles and took the surname Mountbatten. Louis and Victoria had 4 children:2.1
Alice (1885-1969), married prince Andrew of Greece and Denmark (1882-1944). The parents of prince Phillip, Duke of Edinburgh2.2
Louise (1889-1965), married (widowed) king Gustaf VI Adolf of Sweden (1882-1973) as his second wife. Sadly the only had a stillborn daughter.2.3
George (1892-1938), the 2nd Marquess of Milford Haven, married to Countess Nadejda Mikhailovna de Torby (1896-1963) Nadejda was was the second daughter of Grand Duke Michael Mikhailovich of Russia and his morganatic wife Countess Sophie von Merenberg. The grandparents of the current (4th) Marquess of Milford Haven.2.4
Louis (1900-1979), informally known as Lord Mountbatten and who was created 1st Earl Mountbatten of Burma. Married to Edwina Ashley (1901-1960), who was the elder daughter of Wilfred William Ashley, later 1st Baron Mount Temple. Louis's nickname among family and friends was "Dickie", although "Richard" was not among his given names. This was because his great-grandmother, Queen Victoria, had suggested the nickname of "Nicky", but to avoid confusion with the many Nickys of the Russian Imperial Family, "Nicky" was changed to "Dickie". Louis and Edwina were the parents of two daughters, who could inherited their fathers titles (because there were no sons and special specifications). It is claimed Louis was the matchmaker for his nephew prince Phillip and then princess Elizabeth.3
. Alexander (1857-1893), was the first prince of modern Bulgaria (1879-1886). In 1886 he resigned the Bulgarian throne and left Bulgaria. Alexander retired into private life and married an Austrian actress: Johanna Loisinger (1865-1951). He assumed the style of Count von Hartenau. Alexander and Johanna had 2 children: Assen (1890-1965) and Marie Therese (1893-1935).4.
Heinrich (Henry) (1858-1893), married in 1885 Beatrice, princess of Great Britain and Ireland (1857-1944), the youngest daughter of Queen Victoria. His children resided in the UK and became lords and ladies with the surname Mountbatten in 1917. His eldest son was created the first Marquess of Carisbrooke in 1917.4.1
Alexander (1886-1960), 1st Marquess of Carisbrooke. Married Lady Irene Francis Adza Denison, GBE (1890 ?1956), the only daughter of the 2nd Earl of Londesborough and Lady Grace Adelaide Fane. They had one child: Lady Iris Mountbatten (1920-1982). She was married 3 times; Joseph Keyes O?Mally, Michael Bryan and William Kemp. Iris had one child by her 2nd marriage: Robin Bryan (1921-1991).4.2
Victoria Eugenie (Ena) (1887-1969) married the Spanish king Alfonso XIII (1886-1941). In all, Alfonso and Victoria Eugenie had seven children, five sons and two daughters. Their eldest son Alfonso and youngest son Gonzalo suffered from haemophilia, which was blamed on Victoria Eugenie. The current Spanish royals descend from Victoria Eugenie?s 4th son, Infante Juan, who is in his turn the father of King Juan Carlos I (and thus grandfather of king Felipe VI).4.3
Leopold (1889-1922), suffered from haemophilia (probably inherited from/through his mother). He died at the age 32 during a hip operation.4.4
Maurice (1891-1914), killed in action during WWI5.
Franz Joseph (Francis Joseph) (1861-1924) At one time, he was considered for the throne of Bulgaria, which eventually went to his brother Alexander. He supposedly proposed to American heiress Consuelo Vanderbilt, whom turned him down. Franz Joseph married Princess Ana Petrović-Njego? of Montenegro (1874?1971), daughter of Nicholas I of Montenegro. They had no children