Alexei is of Greek origin, meaning 'defender of mankind.' It was popularized by Tsar Alexander II of Russia during the 19th century. In Russian culture, Alexei is often considered a variant spelling of Alexis, which has been used by several members of the Romanov dynasty.
"The name Alexee experienced a peak in popularity during the year 2002 with eleven births, while maintaining an average of around six to ten births per year between 1996 and 2007."