Complex sentence: In 1860 he was elected at a by-election as Member of Parliament (MP) for Nottinghamshire South, a seat he held until 1866, when he succeeded his father in the earldom and took his seat in the House of Lords.
Split into simpler sentences: In 1860 he was elected Member of Parliament for Nottinghamshire South, a seat he held until 1866. The latter year he succeeded his father in the earldom and took his seat in the House of Lords.