Sir Walter Calverley Trevelyan was born in Newcastle upon Tyne to Sir John Trevelyan 5th Baronet and Maria Trevelyan nee Spencer Wilson. He was educated at Harrow and University College Oxford. After University Trevelyan pursued interests in geology and natural history, and became a supporter of phrenology and temperance.

In 1833 he married Pauline Jermyn, daughter of the Reverend Doctor George Bitton Jermyn, Vicar of Swaffham Priory, and Catherine Rowland. Pauline shared Trevelyan's interests in natural history, particularly botany, and the pair traveled extensively throughout Europe.

In 1846 Trevelyan succeeded to his title and the family estates of Nettlecombe and Wallington. He continued to pursue diverse interests, co-editing a volume on the Trevelyan Papers, becoming president of numerous societies including the Phonetic Society, the United Kingdom Alliance for the Suppression of the Liquor Traffic, and of the National Temperance Society. He frequently donated specimens and money to museums, libraries and learned societies.

Pauline became an important patron of the arts, maintaining a close friendship with John Ruskin until her death. Her fondness for the Pre-Raphaelite movement is reflected in refurbishments made at Wallington Hall, in particular the Great Hall. She died in 1866 during a visit to Switzerland, accompanied by Trevelyan and Ruskin.

In 1867 Trevelyan married Laura Capel, daughter of Capel Lofft, lawyer of Troston Hall.

Trevelyan died at Wallington in 1879.

George Lowthian Trevelyan was educated at Sidcot School and Trinity College Cambridge, reading history. He worked as an estate manager and wood craftsman but the majority of his life was spent working in education. He was involved with alternative teaching methods, including the Alexander Technique and Steiner education, and was instrumental in the development of Attingham Park adult education college. In 1940 he married Editha Helen Smith [Helen], and the pair had one adopted daughter. During World War II, George undertook military service on the home front. In later life he became increasingly involved with the Spiritualist movement, and published a number of books.

Geoffrey Trevelyan was educated at Oldfield School and Trinity College Cambridge, reading engineering. In 1941 he began working at De Havilland aircraft. In 1947 he married Gillian Isabel Wood. The pair had two children. Geoffrey lived at St Albans until his death, and established the St Albans Civic Society.

Sir Charles Edward Trevelyan was born in Nettlecombe, Dorset, to George Trevelyan, Archdeacon of Taunton and Harriet Trevelyan nee Neave. He was educated at Charterhouse Grammar School and Haileybury College. He then studied languages at Fort William College in Calcutta, and was assigned as assistant to Sir Charles Metcalfe, resident of Delhi, in January 1827.

Metcalfe was soon replaced by Sir Edward Colebrooke. In June 1829 Trevelyan wrote to the Government of Bengal accusing Colebrooke of corruption and accepting bribes. Following a government investigation, Colebrooke was dismissed from service.

Trevelyan later became guardian to the Raja of Bharatpur, before leaving Delhi for Calcutta in 1831 to become under secretary to the foreign department of the Government of India. In this role he wrote reports on topics including transit duties and education. In 1836 he became secretary to the Sudder board of revenue.

In 1834 Trevelyan married Hannah More (1807-1873), sister of historian and politician Thomas Babington Macaulay. The pair would have three children; Margaret Jean Trevelyan (1835-1906), George Otto Trevelyan (1838-1928) and Alice Frances Trevelyan (1843-1902).

In 1838 Trevelyan returned to England, and became assistant secretary to the treasury. A position he held for 19 years. While in this position he oversaw provision of relief for Ireland during the Great Famine in Ireland and worked towards revision of military expenditure and reorganization of the civil service.

Trevelyan was offered governorship of Madras in 1858, taking up the position in spring 1859. In this role he worked towards establishing a municipal corporation, improving water and sanitary conditions, introducing a new police force and establishing land ownership rights.

Trevelyan was opposed to the government's proposed tax increases, intended to recover expenses resulting from the Indian Rebellion of 1857. His public objections to the legislation being passed was met with disapproval, and he was notified of his removal from office in May 1860.

Two years later he returned to India as financial member of the Indian Council at Calcutta, where he served until 1865.

In 1874 he was created a Baronet, and the following year he married Eleanor Anne Campbell (d.1919). In 1879 Trevelyan inherited the Wallington estate in Northumberland, following the death of his cousin Walter Calverley Trevelyan, without issue.

He died in London in 1886.

Author of 'Life and Letters of Zachary Macaulay' (1901)

Mary Katharine Bell was born in Kirkleatham on 12 October 1881, to Sir Thomas Hugh Bell, second baronet and iron master, and his second wife, Lady Florence Eveleen Eleanor Bell (née Olliffe), author and social investigator. She was the youngest of their three children, and was the stepsister of the traveller, writer and political figure Gertrude Bell, and the granddaughter of Sir Isaac Lowthian Bell, first baronet, steel manufacturer and MP. Mary, known as Molly to close friends and family, studied briefly at Queen's College before she began a relationship with Liberal MP Sir Charles Philips Trevelyan, third baronet (1870-1958). After their marriage in January 1904, Mary became a successful political hostess at their home in London, arranging dinners and parties for political friends and associates. Around this time, Mary became president of the Northumberland Women's Liberal Federation (WLF), and became a popular speaker around the country. She favoured women's suffrage, an issue which deeply divided the WLF, but disliked the militancy associated with the movement. Mary actively aided her husband in his work, translating German material on land reform, and campaigning in his favour at each election, including that of 1918 in which he was attacked for his opposition of the First World War.

After Charles inherited the Trevelyan ancestral home of Wallington Hall, Northumberland, in 1928, the pair devoted much of their lives to the estate and the village of Cambo, becoming invested in the welfare of their tenants and establishing a pension plan for local schoolchildren. Mary was active in many local, national and international groups including the Workers' Educational Association and the Federation of Women's Institutes, as well as founding local branches of the Girl Guides, the Women's Institute and the Band of Hope. She served on the national executive of the National Federation of Women's Institutes, played a leading role in the Folk Dance and Northumbrian Pipers societies, and played a key role in the establishment of the Council for the Preservation of Rural England in 1926, becoming a representative and founding committee member. In 1963, she was awarded with an OBE for her years of public service to politics and various good causes. Mary died at St Catherine's Nursing Home in Newcastle Upon Tyne on 8 October 1966, and her ashes were scattered on moorland near Winter's Gibbet on the Wallington estate.

In addition to estate work she was a JP and was active with numerous local, national, and international organizations, such as the Workers' Educational Association and the Association of Country Women of the World. She founded branches of the Girl Guides and the Women's Institute in Cambo, and served on the national executive of the National Federation of Women's Institutes for many years. In keeping with her temperance principles she also founded in Cambo a Band of Hope, which local children were pledged to join at a young age. She also played a leading role in the Folk Dance and Northumbrian Pipers societies, and made music an important feature of her family's life. Singing songs, accompanied by Molly on the piano, was a regular part of their domestic routine, and she and Charles also delighted their children, among them George Lowthian Trevelyan, by regularly reading to them from a diverse selection of classic literature. Such activities took the place of attending church on Sundays, for while Molly was Unitarian, Charles was agnostic. In appearance her clothes, hairstyle, and pince-nez gave her a Victorian air, and one contemporary described her as attractive in a 'no nonsense' sort of way. Her decades of public service, to politics and various other good causes, were recognized with an OBE in 1963, shortly before her death at St Catherine's Nursing Home, Newcastle upon Tyne, on 8 October 1966. Her ashes were scattered on moorland near Winter's Gibbet on the Wallington estate.

Wife of Charles Edward Trevelyan and sister of historian and politician Thomas Babington Macaulay