Jane and May Morris: A Biographical Story 1839-1938. Rivers Oram Press/Pandora List, 1986.
Pre-Raphaelite Women: Images of Femininity in Pre-Raphaelite Art. London: Weidenfeld & Nicolson, 1987.
Women Artists and the Pre-Raphaelite Movement. London: Sphere, 1987. (co-authored with Pamela Gerrish Nunn)
The Legend of Elizabeth Siddal. London: Quartet, 1989.
The Woman's Domain: Women and the English Country House. London: Viking, 1990. (co-authored with Trevor Lummis)
Christina Rossetti: A Literary Biography. London: Jonathan Cape, 1994.
Bloomsbury Women: Distinct Figures in Life and Art. London: Pavilion Book, 1995.
The Pre-Raphaelites: Their Lives in Letters and Diaries. London: Trafalgar Square, 1996.
The Pre-Raphaelites. London: National Portrait Gallery, 1998. (Character Sketches series)
Dante Gabriel Rossetti: Painter and Poet. London: Weidenfeld & Nicolson, 1999.
Dante Gabriel Rossetti: Collected Writings. London: J. M. Dent & Sons, 1999.
Christina Rossetti: Selected Poems. London: Phoenix, 2002. (editor)
Spoken, Broken and Bloody English: The Story of George Bernard Shaw, Linguaphone and Eliza Doolittle, London: Linguaphone Institute, 2002. With foreword by Lord Quirk. ISBN0747309493
Black Victorians: Black People in British Art 1800-1900. London: Lund Humphries, 2005. (editor)
William Morris and Red House: A Collaboration Between Architect and Owner. National Trust Books, 2005. ISBN1905400012
The Pre-Raphaelite Circle. London: National Portrait Gallery, 2005. (Insights series)
A Guide to Victorian and Edwardian Portraits. London: National Portrait Gallery in association with the National Trust, 2011. (co-authored with Peter Funnell)
The Pre-Raphaelite Circle. London: National Portrait Gallery.