Holland has studied and researched Wilde's life for more than thirty years. He is the editor of
Irish Peacock and Scarlet Marquess, the first uncensored version of his grandfather's 1895 civil
trial. (The book is titled
The Real Trial of Oscar Wilde for release in the US.) Holland has criticised
Richard Ellmann's 1987 biography,
Oscar Wilde, as inaccurate, particularly his claim that Wilde had
syphilis and transmitted it to Constance. According to
The Guardian, Holland has "unearthed medical evidence within private family letters, which has enabled a doctor to determine the likely cause of
Constance's death. The letters reveal symptoms nowadays associated with
multiple sclerosis but apparently wrongly diagnosed by her two doctors. One, an unnamed German 'nerve doctor', resorted to dubious remedies and the other,
Luigi Maria Bossi, conducted a botched operation that days later claimed her life." Holland has also written
The Wilde Album, a small volume that included hitherto unpublished photographs of Wilde. The book concerns how the scandal caused by Wilde's trials affected his family, most notably his wife, Constance, and their children,
Cyril and
Vyvyan. In 2006, his book
Oscar Wilde: A Life in Letters was published, and his volume
Coffee with Oscar Wilde, an imagined conversation with Wilde, was released in the autumn of 2007. Holland's play
The Trials of Oscar Wilde, co-authored with John O'Connor and re-enacting the 1895 trials of Lord Queensberry for libel and Oscar Wilde for gross indecency, toured the United Kingdom in 2014 as a production by the European Arts Company. In October 2025 Holland published
After Oscar: The Legacy of a Scandal, his long anticipated retrospective which debunks many biographical misunderstandings, and family myths, that have developed since Wilde's release from prison in 1897 and his death in 1900. ==Personal life==