I have the book Michael & Natasha by the Crawfords and agree that it is a very good book on this subject. The authors do a good job of making these two tragic characters appear quite sympathetic, especially Michael. He was so handsome and seemed so romantic and tender with Natasha and her children; he was truly a kind-hearted fellow. I think that their romance was just as touching and compelling as Nicholas and Alexandra's, although perhaps it does not appeal to quite so many because it was not such an innocent affair and Natasha may not be viewed as such a sympathetic character as Alexandra.
It is unfortunate that this couple had to live at a time when divorce was so looked down upon. The authors write, "The uncompromising views of the Dowager Empress, for example, were shared with no less absolute conviction in England by her sister Queen Alexandra, as well as by her daughter-in-law the Empress Alexandra. Their doors were closed firmly in the face of any divorcee, as were those of hostesses, royal or otherwise, who continued to believe, and would go on so believing for half a century more, that divorce was a disgrace which condemned both guilty and innocent parties to the shadows" (pg. 34).
If I have one criticism of this book, however, it is that it seems very one-sided in portraying Michael and Natasha as the hero lovers who fought against all odds for their love, and the Tsar & Tsarina as the jealous villains trying to keep them apart. They are especially hostile towards Alexandra, and seem to play into the typical generalization we have all read so many times of Nicholas as the weak husband controlled by a domineering and hysterical Alexandra. They refer to the Tsarina as Nicholas's "suffocating, tight-mouthed wife" (pg. 44). They put into question her very state of mind, stating: "Natasha was certainly formidable and she would not have survived the past years if she had been otherwise. But at least she was entirely sane. Some people wondered if the same could be said about Alexandra" (pg. 179). And they also portray Alexandra as insanely jealous, on one occasion even ordering some pictures of Natasha that were on display at a studio window taken down by the police in front of a crowd. The Imperial couple are deemed as being very closed-minded and looking down upon anybody who did not share their exemplary family values. I assume that these are all statements based in fact, and admittedly I will give credit to the authors for not being afraid to show the uglier side of the Tsarina by writing about these accounts. On the other hand, if one steps back for a moment and tries to see things from her point of view, one can understand her concern. Nicholas and her were a product of a time when divorced people were looked badly upon, however unfair that may seem to us, and if Michael were to become Tsar one day, they didn't want a twice-divorcee as Empress and her son becoming Tsar. In summary, this is a very interesting book from which I learned things about both couples that I didn't know before.