Recently I watched this ITV mini-series and thoroughly enjoyed it. It is based on the novel by Julian Barnes. I haven't read it, so I cannot say how closely to the book it was written, but I did read ACD's autobiography "Memories and Adventures", a collection of his correspondence "Arthur Conan Doyle: A Life in Letters", and a biography by Daniel Stashower "Teller of Tales: The Life of Arthur Conan Doyle".
Judging by what I gathered from these three sources, the mini-series is quite historically accurate, describing the period of ACD's life when he suffered depression after the passing of his first wife and how the Edalji case helped him to cope by giving him a purpose. In the series, just as in real life, ACD dedicated a lot of energy to investigating the case of a wrongly accused half-Parsi half-English solicitor George Edalji and launched a high-profile media campaign to clear Edalji's name. And while the series has a fictional side to it, with pursuits and fights, it was great to see the real life aspects covered, like Arthur's relationship with Jean Leckie, his wife-to-be, and the disapproval from his sister Connie and her husband E. W. Hornung (albeit this aspect was somewhat different in real life). The series even includes the small detail that George Edalji was invited to Arthur and Jean's wedding.
There is a distinct Holmes-Watson dynamic between ACD and his secretary major Alfred H. Wood as they run around investigating, which was an endearing touch. All in all, I think the series is a nice blend of fact and fiction. Even though Martin Clunes seems a bit long in the tooth for the role, it doesn't matter much. He bears a striking resemblance to ACD in Doyle's older years. I wonder why, though, the series turns the Edalji case into a story of personal feud rather than racial prejudice as it was in real life. Otherwise it's a very well-made period drama.