| Marquessate of Milford Haven | |
| Creation Date: | 7 November 1917 |
| Heir Apparent: | Henry Mountbatten, Earl of Medina |
| Remainder To: | the 1st Marquess's heirs male of the body lawfully begotten |
| Subsidiary Titles: | Earl of Medina Viscount Alderney |
| Status: | Extant |
| Motto: | IN HONOUR BOUND |
Marquess of Milford Haven is a title in the Peerage of the United Kingdom.
The marquessate of Milford Haven was created in 1917 for Prince Louis of Battenberg, the former First Sea Lord, and a relation by marriage to the British Royal family, who amidst the anti-German sentiments of the First World War abandoned the use of his German surname and titles and adopted the surname Mountbatten, an Anglicized version of the surname Battenberg. He was at the same time made Earl of Medina and Viscount Alderney, also in the Peerage of the United Kingdom. The title honours the Welsh seaport and shipyard town of Milford Haven.
, the titles are held by his great-grandson, the fourth Marquess, who succeeded his father in 1970.
The family lived at Lynden Manor at Holyport, Berkshire, now split into four houses. A later seat was Moyns Park in Birdbrook, Essex. The 1st and 3rd Marquess of Milford Haven are buried at St. Mildred's Church, Whippingham; the 2nd Marquess is buried in Bray Cemetery, Bray, Berkshire.
The present Marquess owns the Great Trippetts Estate in Sussex.
Other titles (1st Marquess onwards): Earl of Medina (UK, 1917) Viscount Alderney (UK, 1917)
The heir apparent is the present holder's son Henry David Louis Mountbatten, Earl of Medina (b. 1991)
Ref:[1]
| Crest: | 1st: Out of a Coronet Or two Horns barry of ten Argent and Gules issuing from each three Linden Leaves Vert and from the outer side of each horn four Branches barwise having three like Leaves pendent therefrom of the last (Hesse); 2nd: Out of a Coronet Or a Plume of four Ostrich Feathers alternately Argent and Sable (Battenberg) |
| Coronet: | A Coronet of a Marquess |
| Escutcheon: | Quarterly: 1st and 4th, Azure a Lion rampant double-queued barry of ten Argent and Gules armed and langued of the last crowned Or within a Bordure compony of the second and third (Hesse); 2nd and 3rd, Argent two Pallets Sable (Battenberg); charged on the honour point with an Escutcheon of the arms of the late Princess Alice of the United Kingdom, namely: the Royal Arms differenced by a Label of three points Argent the centre point charged with a Rose Gules barbed Vert and each of the other points with an Ermine Spot Sable |
| Supporters: | On either side a Lion double-queued and crowned all Or |
| Motto: | In Honour Bound |