Nicholas And Alexandra: by Robert Massie.

Alexandra had a choice of at least two possible consorts from high royalty of Europe, and chose to marry Nicholas, liking him better from the possible offers. And the times were turbulent but they had a happy life as a couple (albeit with dire worries as parents since their only son was haemophiliac, but that could happen to normal people too) - until the turbulence could not be kept out of their personal and family life, with some events of Russian revolution eerily imitating those from the French not too long before.

One wishes they had been allowed to survive as people, just a family, as many did escaping to various other countries - Paris was a favourite choice of White Russians and had a considerable colony - and in fact they could have survived in England, since the king was a first cousin of both Nicholas and Alexandra, former through his mother and latter through Queen Victoria. But the king of England was advised not to give refuge to the Russian deposed royals, since this would be seen with disfavour by the Russian new government and possibly by the people of England with liberals winds blowing strong.