As Lord Dalmeny he was a prominent cricketer and he played two first-class matches for Middlesex in 1902. He served as captain of Surrey County Cricket Club. He played in 102 first-class matches in all, scoring 3551 runs at an average of 22.47, including 2 centuries with a highest score of 138. He was a hitter of notable power and though never consistent he could on occasions “knock the best bowling all over the field”, as when he hit 58 against Hallam on a difficult wicket at The Oval in 1905. Rosebery was notable in horseracing circles for winning The Derby with Blue Peter and Ocean Swell, and winning most other classic British flat races, with horses bred at his Mentmore and Crafton Studs.
Political career and later life
He commenced his political career by being elected Liberal Member of Parliament for the Scottish seat of Edinburghshire. This was a county, better known by its modern name of Midlothian, which was an area where the Roseberys had long been prominent landowners. Dalmeny was one of almost 400 Liberals returned in the great landslide victory of the 1906 election. He retired from the House of Commons in January 1910. At the time of his death he was the last survivor of the 1906 Liberal MPs. Rosebery entered the House of Lords on the death of his father in 1929. The same year he was appointed Lord Lieutenant of Midlothian, a post he held until 1964. In 1938 he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Hugh Macmillan, Baron Macmillan, Sir Thomas Henry Holland, James Pickering Kendall and James Watt. In February 1941, during the Second World War, he was appointed Regional Commissioner for Civil Defence in Scotland. When the wartime coalition government broke up in 1945, Winston Churchill formed a caretaker administration to hold office until the 1945 general election. The new government was composed of members of the Conservative Party and the small groups which had allied with it in the National governments in office 1931–1940. Amongst these allies was the National Liberal Party to which Rosebery belonged. One of the most unexpected appointments Churchill made was to install Rosebery as a member of the Privy Council and Secretary of State for Scotland. Both men had served together in the Liberal Parliamentary Party in the 1906–1910 Parliament. The caretaker Ministry was in office May to July 1945. So brief was his tenure at the Scottish Office that during the Royal Commission on Scottish Affairs he declined to give evidence on the grounds that he did not know what to say. Reputedly, his last words prior to his departing from the Scottish Office were "Well. I didn't make a bad job of this, did I? Didn't have the time". He was created a Knight of the Order of the Thistle in 1947 by King George VI. Rosebery was President of the National Liberal Party 1945–1957. He was also appointed Chairman of the Royal Fine Art Commission for Scotland in 1952. He died at Mentmore House in Buckinghamshire on 30 May 1974.
Family
In 1909, Harry Primrose married Dorothy Alice Margaret Augusta Grosvenor, daughter of Lord Henry George Grosvenor. They had a son, Archie Primrose, Lord Dalmeny, and a daughter, Lady Helen Dorothy Primrose. They divorced in 1919. Harry Primrose remarried in 1924, to Dame Eva Isabel Marian Strutt, daughter of the 2nd Baron Aberdare of Duffryn. Their only child, Neil Archibald Primrose, was born in 1929, and became the 7th Earl of Rosebery on the death of his father on 31 May 1974.
