Question: The Theater des Westens (Theatre of the West) is one of the most famous theatres for musicals and operettas in Berlin, Germany, here Ballets Russes appeared with which Russian prima ballerina of the late 19th and the early 20th centuries, and was  a principal artist of the Imperial Russian Ballet?
Sentence (from "Alicia Markova"): She was the first British dancer to become the principal dancer of a ballet company and, with Dame Margot Fonteyn, is one of only two English dancers to be recognised as a prima ballerina assoluta.
Relevant evidence: No