[3] In 2007, as part of the commemoration of the bi-centenary of the Abolition of the Slave Trade Act, Lascelles was executive producer of the theatrical project by Geraldine Connor entitled Carnival Messiah that was staged in the grounds of Harewood House, which was built in the 18th century with funds from slave trading.

[4][5] Following Connor's death in 2011, Lascelles organised a concert in her memory at West Yorkshire Playhouse,[6] and he is a founder and patron of the Geraldine Connor Foundation, established in 2012 to continue her work and vision by bringing people together through arts and culture.

[7] As Earl of Harewood, he continues the tradition begun by his father in 1961 by serving as the honorary lifetime president of Leeds United Football Club.

The group has called on the British prime minister and King Charles III to make a formal apology on behalf of the United Kingdom.

[10] On 12 February 1979, at St Mary's Church, Paddington, London, Lascelles married Margaret Rosalind, daughter of Edgar Frank Messenger.