 She had two sons with him, the future King Alexander, born 1876, whose godfather was Tsar Alexander II of Russia, and his younger brother Sergei (Sergej), who died just a few days after his birth in 1878.When Prince Milan proclaimed the Kingdom of Serbia in 1882 after securing international recognition, Princess Natalie assumed the title and rank of a queen.At the Easter reception of 1886, Queen Natalie publicly slapped the wife of the Greek ambassador.