He was at the same time made Earl of Medina and Viscount Alderney, also in the Peerage of the United Kingdom.

[1] The title honours the Welsh seaport and shipyard town of Milford Haven.

As of 2016[update], 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.

The heir apparent is the present holder's son Henry David Louis Mountbatten, Earl of Medina (b.