Charles Philips Trevelyan (1870-1958) was the first son of George Otto Trevelyan and Caroline Lady Trevelyan of Wallington Hall, Northumberland. Educated at Harrow and Trinity College Cambridge, Charles' political career began with a role as Private Secretary to Lord Houghton at Dublin Castle. However he did not enjoy the work and returned to England in 1893. After his return to England, he ran an unsuccessful campaign as Liberal candidate for North Lambeth. While standing as Liberal candidate for Elland in North Yorkshire, Charles travelled through North America, the Pacific Islands, Australia and New Zealand with Beatrice and Sidney Webb. On his return to England in 1899 he won a by-election, becoming the representative of Elland. In 1908 he was also made Parliamentary Secretary to the Board of Education.
In 1904 Charles married Mary Katharine Trevelyan nee Bell (1881-1966) [Molly], daughter of Hugh and Florence Bell, and half-sister of the archaeologist and explorer Gertrude Bell. The pair had seven children together, six of whom survived to adulthood. The early years of their marriage were split between Cambo House on the Wallington Estate in Northumberland, and 14 Great College Street in Westminster.
When Britain declared war with Germany in 1914, Charles resigned his position in the government in protest – a move which attracted much criticism from his peers, the press and the public. Alongside others who disagreed with the conflict, Charles helped to establish the Union of Democratic Control (UDC) – a political group who publicly criticized the activities of the British government during World War I and advocated a peaceful resolution. As an active member, Charles promoted the UDC and its activities extensively, publishing articles and pamphlets, and giving talks around the country.
During his involvement with the UDC, Charles came into contact with many figures of the growing Labour Party. In 1918 Charles announced that his political sympathies were more aligned with Labour than the Liberals. Following Armistice with Germany that same year, Charles ran as a member of the Independent Labour Party for Elland. He lost his constituency of 18 years to a Conservative candidate, as part of the landslide Conservative coalition victory.
In 1921 Charles articulated his transition between parties in a short publication entitled From Liberalism to Labour. The following year he stood as Labour candidate for Newcastle Central and won. In the first Labour government of 1924, Charles was made President of the Board of Education, however his impact was limited by the short duration the government served. When Labour were re-elected to government in 1929, Charles was given the same role. However, he resigned after becoming frustrated with the government's reluctance to pass radical policy, in particular his bill to raise the school leaving age. Later that year Charles lost his seat at Newcastle to a Conservative candidate.
Following these disappointments Charles announced his retirement from politics. His parents' recent deaths had resulted in the family moving into Wallington Hall and taking on the management of the large estate. This gave Charles the opportunity to put into practice some of his socialist ideals, including the introduction of child benefit payments to tenant families and the establishment of pensions. In 1936 Charles announced he would bequeath the Wallington Estate to the National Trust. This became reality on his death in 1958.
Charles' wife Mary supported Charles' political career throughout her life, assisting with campaigning, hosting parties for political figures and in later years contributing to the running of the Wallington Estate. Early in their marriage she served as Chairman of the Northumberland Women's Liberal Foundation and she later became a Justice of the Peace. She also served on committees for the Campaign for the Protection of Rural England, the National Trust, the National Federation of Women's Institute and the Association of Country Women of the World. She was awarded the OBE in 1963.

Pauline Dower was educated at Sidcot School and Reading College, studying agriculture. She worked in dairy farming and as a shepherd before marrying Architect John Gordon Dower in 1929. The pair had three children. During World War II John contracted tuberculosis, and the family relocated from London to Yorkshire, then to Cambo. After John's death in 1947, Pauline continued his work to establish National Parks, serving on the National Parks Committee. In later life Pauline was awarded the OBE and became a Justice of the Peace.