the current Pretender to the throne of Russia is one Maria Vladimirovna. Her full title is Her Imperial Highness Grand Duchess Maria Vladimirovna of Russia.

of course, the Russian monarchy was abolished in 1917.

she's also 109th in line to the throne of the UK!

http://en.wikipedia.org/wiki/Maria_Vladimirovna%2C_Grand_Duchess_of_Russia