From 1833 to 1840, Cavendish served as an officer in the
10th Light Dragoons. After leaving the army, Cavendish served as a
Lieutenant in the disembodied
Royal Buckinghamshire Militia (King's Own), being promoted to
Captain in 1846. After the
militia was revived the Duke of Devonshire raised the
2nd Derbyshire Militia (Chatsworth Rifles) in 1855 and commissioned him as captain in the new regiment. In 1847, he was elected as a
Liberal Member of Parliament for
Peterborough, a seat he held until 1852, and later represented
Buckinghamshire, serving alongside
Benjamin Disraeli from 1857 to 1863, when he succeeded his father in the barony and took his seat in the
House of Lords. His father, a Member of Parliament for nearly forty years, had been created Baron Chesham of Chesham on 15 January 1858. ==Personal life==