[10] After ten years in opposition, the Liberals again came to power in December 1905 under Sir Henry Campbell-Bannerman, who appointed Tweedmouth First Lord of the Admiralty,[11] with a seat in the cabinet.

Chancellor of the Exchequer H. H. Asquith eventually stated that the correspondence was "a purely personal and private communication, conceived in an entirely friendly spirit" and no action was taken.

[12] However, when Asquith succeeded Campbell-Bannerman as prime minister in April 1908 Tweedmouth was removed as head of the Admiralty and became Lord President of the Council.

[8] He suffered a nervous breakdown in June 1908, a condition which was said to partly explain his indiscretion in communicating with the German Emperor on naval matters.

[12] Lord Tweedmouth married Lady Fanny Octavia Louise (1853–1904), daughter of John Spencer-Churchill, 7th Duke of Marlborough and aunt of Sir Winston Churchill, in 1873.

From 1883 until 1896, he was an owner of and investor in Rocking Chair Ranche located in Collingsworth County, Texas, along with his father, The 1st Baron Tweedmouth, and his brother-in-law, The 7th Earl of Aberdeen.