Alexander Mountbatten, 1st Marquess of Carisbrooke

Alexander, known as Drino, was born in 1886 at Windsor Castle in Berkshire and was educated at Wellington College and at the Britannia Royal Naval College. His father was Prince Henry of Battenberg, the son of Prince Alexander of Hesse and by Rhine and Julie née Countess of Hauke. His mother was Princess Beatrice of the United Kingdom, the fifth daughter and the youngest child of Queen Victoria and Prince Albert.

Prince Henry of Battenberg was the product of a morganatic marriage and took his style of Prince of Battenberg from his mother, Julia von Hauke, who was created Princess of Battenberg in her own right. At his birth, Alexander was styled His Serene Highness Prince Alexander of Battenberg because the child of a morganatic marriage is ineligible for "Grand-Ducal Highness" status. However, three weeks after his birth, on 13 December 1886, he was styled His Highness under a Royal Warrant passed by his grandmother Queen Victoria.

He was baptised in the White Drawing Room of Windsor Castle on 18 December 1886. His godparents were Queen Victoria of the United Kingdom (his maternal grandmother), Prince Alexander of Hesse and by Rhine (his paternal grandfather), the Prince of Wales (his maternal uncle), Prince Alexander of Battenberg (his paternal uncle), and Princess Irene of Hesse and by Rhine (his maternal first cousin and paternal second cousin).

Alexander was the brother-in-law to Alfonso XIII of Spain, who married Alexander's sister, Princess Victoria Eugenia, in 1906.

Lord Carisbrooke, who received no state allowance, became the first member of the British royal family to work in the commercial sector. He began his career working as an entry-level clerk in the offices of Lazard Brothers bankers. He later worked for a company that oversaw housing estates, and before long he took control of social work for the tenants.

Later he became a director of Lever Brothers and several other prominent corporations.

On 19 July 1917, he married Lady Irene Denison (4 July 1890 – 16 July 1956), the only daughter of the 2nd Earl of Londesborough and his wife, Lady Grace Adelaide Fane, at the Chapel Royal of St James's Palace.

Lord and Lady Carisbrooke had one child, a daughter:

Lady Iris Mountbatten (13 January 1920 – 1 September 1982)

Carisbrooke was likely homosexual or bisexual; according to the published diaries of Cecil Beaton, in his later years, Lord Carisbrooke had a longtime male lover, Simon Fleet. More is written about Lord Carisbrooke and his wife in the published diaries of James Lees-Milne and Henry "Chips" Channon.