one of the most effective social and industrial reformers in 19th-century England. He was also the acknowledged leader of the evangelical movement within the Church of England.

He was the eldest son of Cropley Cooper (a younger brother of the 5th Earl of Shaftesbury) and of Anne, daughter of the 4th Duke of Marlborough. He became Lord Ashley when his father succeeded to the earldom in 1811, was educated at Harrow and Christ Church College, Oxford, and succeeded his father as earl in 1851.

A member of the House of Commons from 1826, Ashley attacked the Reform Bill of 1832 for widening the franchise, but he favoured the political emancipation of Roman Catholics and the repeal in 1846 of the Corn Laws (import duties on grain). Becoming a lunacy commissioner in 1828 and commission chairman in 1834, he secured passage of the Lunacy Act of 1845, the first British statute to treat the insane as “persons of unsound mind” rather than social outcasts. He early was associated with the factory reform movement led by Richard Oastler and, in the House of Commons, by Michael Thomas Sadler. In 1833, after Sadler's defeat in an election, Ashley replaced him as parliamentary leader of the movement for shortening the working day in textile mills to 10 hours. Although popularly known as Lord Ashley's Act, the Ten Hours Act of 1847 was passed while he was temporarily out of the House of Commons (January 1846–July 1847). In his working for further factory reform legislation, he was accused by the radical reformer John Bright not only of ignorance of actual working conditions in factories but also of unconcern for rural labourers (labour, hours of), including those on the Shaftesbury estates.

By his Mines Act of 1842, Ashley excluded all women and girls and all boys under the age of 10 from underground coal-mine employment, in which he had found boys aged 4 or 5 years. While serving as a member of the short-lived General Board of Health (1848–54) and afterward, Shaftesbury (who succeeded to the earldom in 1851) insisted that the government sponsor new low-cost housing projects for urban workers and carefully inspect housing that already existed. During his 39 years as president of the Ragged Schools (ragged school) Union, that organization enabled about 300,000 destitute children to be educated free at what were called ragged schools or industrial feeding schools. He also served as president of the British and Foreign Bible Society, founded numerous Young Men's Christian associations and Workingmen's institutes, and financially supported missionary societies for Nonconformist faiths as well as for the Church of England.

As a staunch evangelical he viewed with alarm the growing ritualism in the Church of England and materially aided Prime Minister Benjamin Disraeli in the passage of the Public Worship Act (1874), which checked the extension of Anglo-Catholic practices.