Well,good question...According to Russian historic Galina Moiseeva Tolstoy and Raevsky families were related...
If you have read "War and Peace" you might have noticed that Tolstoy,while described battle at Borodino,mentioned brave General Nikolai Raevsky(he used here the real name the grandfather of our "Vronski")...his grandson,also Nikolai(1839—1876) went to Serbian-Turskish war(served under General Chernyaev) got killed and was buried in Serbia...so,Tolstoi was obviously well informed about the family...
Tolstoy used prototypes of real people he knew or knew about for his novels.Thomas Mann also confirms that in his preface for the American edition of the novel "Ana Karenina".In this novel the Vronsky character also goes to Serbian-Turkish war after a love failure...At the very place Raevsky got killed and buried,the people of that place built the Russian church which was later bought by Queen Natalia of Serbia,who considered herself very much a Russian...here is a picture of his grave:
http://mw2.google.com/mw-panoramio/photos/medium/41896763.jpgAnd this is that church:
http://upload.wikimedia.org/wikipedia/commons/e/e7/Gornji_Adrovac%2C_l%27%C3%A9glise_russe.jpgAnd here are some images of Raevsky himself:
http://upload.wikimedia.org/wikipedia/sr/a/a5/Pukovnik_Rajevski.pnghttp://sr.wikipedia.org/apple-touch-icon.pngHope this helps...I just wanted to make the connection between King Alexander and his upbringing,family connections with many Russian refuges(among the mentioned noble families) that came to Serbia after the revolution during his reign...