There are at least 4 records of nobility at the St. Petersburg, Russia, Archives for this surname. Nobles during the time of the Czar had to register their sons when they were born as nobles including the documentation for it........i.e., family trees. Even when the Czar had no domination over Poland........or Lithuania.........these records were kept in Poland and Lithuania where people of this surname resided. Remember the two countries were one after the 14th century when the rulers of both countries married. After WWII many records were taken by the Russians back to Russia.......some to Moscow, and some to St. Petersburg. The nobility and military records are located in St. Petersburg. These people lived under Stalin's repression and are listed in records in St. Petersburg: Mikhail, son of Iosif, and Roman,son of Alexander. Roman was born in 1893 in Warsaw, Poland, and was shot in Leningrad.......now St. Petersburg.....in 1937. Mikhail was born in 1901 in Grodno Province, village of Novosiolki, lived in Barancha of Kushvinski district of Sverklovsk (in the Urals), and was shot in 1937 by Stalin's men in what is now Ekaterinburg. The records of nobility are from 1860, 1876, 1883, and 1891.
There is also mention of a Kaetan Bajkowski who graduated from the Mogilev Gymansium in 1840.......a time when only the nobility went to gymnasiums. Also a Stanislaw (sp? because it is written in Polish and my computer isn't reading the characters correctly) Bajkowski who I think it says was born in 1638 and died in 1667. More records most likely exist in St. Petersburg.
You must remember that the Bajkowski family lived in what is now Belarus, Lithuania, and Poland depending on where their land holdings from their positions were located. The men listed here from the 1900s are most likely siblings of some who emigrated to the US and other countries. The nobility all spoke Polish.......and all used the Polish spelling of the name on official documentation as far as I know. I found this out in researching Baikauskas. I found that most of those now using Baikauskas......or some form of it.......were using Baikowski, or Bajkowski on entry to the US. It is the surname they usually married under......and often at least the first of their children were registered under. It was a source of pride to them to be Baikowski.....or Bajkowski.....as it signified their nobility wherever they lived.