Mary of Scotland stars Kathryn Hepburn as the doomed monarch with Florence Eldridge as Elizabeth Tudor, Fredric March as Bothwell and a lengthy supporting cast including Douglas Walton as Darnley, Alan Mowbray as Throckmorton and Donald Crisp as Huntly. While the film seems based on the true events of Mary Stuart's life, there are problems with the film that made it difficult to watch.
It's a very stage-like production that hasn't adapted to film very well. A lot of the scenes are static with very little movement and they last for quite a while. There are relatively few Scottish accents in attendance and those that are Scottish are not always convincing. The love story between Mary and Bothwell doesn't feel very realistic, possibly as a result of the scope of the film being on politics rather than romance.The effects are over-played and unnecessary and some of the dialogue delivery is cringe-worthy. Florence Eldridge comes across as far more comfortable in her role (though she is nowhere near the standard of Elizabeth I that Bette Davis attained in her two outings, reviewed here and here). I don't think playing a queen was beyond Hepburn - I just think that a lot of issues contrived to make this film difficult to enjoy. Hepburn herself later admitted that she respected Elizabeth and not Mary, calling the latter a 'ninny'.
So those are the bad points. However, there were sparks in the film that helped elevate it a little. For instance, Douglas Walton's performance as the effeminate Darnley is excellent to watch and the meeting scene between Elizabeth and Mary adds tension to the film - perhaps too late to save it. There is also a moment where the peasants begin singing of their loyalty to their Scottish queen in a standout scene which wasn't hampered, like most, by its length.
There is nothing inherently wrong with stage-like productions but I don't think Mary of Scotland worked particularly well. Whether this was because of Hepburn's disbelief in her role, a domineering director or screenwriter or simply a few errors of judgement, it doesn't really matter. Watch for Eldridge and Walton, not for Hepburn or March.