He was educated at Eton and Trinity College, Cambridge, where he was a member of the Pitt Club.
Therefore he was one of the few Liberal MPs who lost their seat in the 1906 election. In December 1908 he was appointed chairman of the Royal Commission on Systems of Election, with the mandate "to secure a fully representative character for popularly elected legislative bodies" and "to consider whether, and how far, they, or any of them, are capable of application in this country in regard to the existing electorate". The commission reported in 1910, recommending the abolition of two member constituencies "as soon as possible".
This was implemented.
The commission also recommended the adoption of an alternative vote system, which was not implemented. In 1911 Cavendish was on Prime Minister Asquith"s list of peers in case the Parliament Acting 1911 was not passed by the House of Lords and was admitted to the Privy Council in 1912.
As President of the Royal Lancashire Agricultural Society, Cavendish visited Lancaster in 1925. He was the Lord of the Manor, residing at Holker Hall (where his descendants remain to this day) and owned the Swan Hotel at Newby Bridge.
He was an active freemason and a keen golfer.
Cavendish married Lady Moyra, daughter of the William Beauclerk, 10th Duke of Street Albans, in 1895.
26th United Kingdom Parliament. 27th United Kingdom Parliament]
Cavendish was elected in the 1895 general election as the Member of Parliament (Member of Parliament) for North Lonsdale. He crossed the floor from being a supporter of the Liberal Unionists to being a member of the Liberal Party in 1904.