Description:William Legge was the eldest son of the 6th Earl of Dartmouth. He was educated at Eton and Christ Church, Oxford. He was styled Viscount Lewisham between 1891 and 1936.
Legge married Lady Rupert Wynn-Carrington, third daughter of Robert Wynn-Carrington, 1st Marquess of Lincolnshire, on 7 December 1905. They had six children.
In 1907, he joined the London County Council and entered Parliament in 1910 as Member of Parliament for West Bromwich, a seat he held until 1918. He was High Bailiff of Westminster from 1930–42.
Legge became 7th Earl of Dartmouth when he inherited his father's titles in 1936. He served with the Staffordshire Yeomanry in the Egypt and Palestine campaign in the Second World War, for which he was awarded the Territorial Decoration.
Following the death of his father-in-law in 1928 Lord Dartmouth acted as Deputy Lord Great Chamberlain until the death of George V in 1936. Lord Dartmouth died in February 1958, aged 77. As he had no surviving male issue, he was succeeded by his younger brother, Humphry Legge.