 He succeeded Lord Digby as lieutenant-colonel commandant on 20 September 1870.Grosvenor was Liberal Party Member of Parliament for Flintshire from 1861 until 1886.On 19 March 1872 he was sworn of the Privy Council and appointed Vice-Chamberlain of the Household by William Ewart Gladstone, a post he held until the government fell in 1874.