Complex sentence: In the Middle Ages, what has become known as ballet had its beginnings in Italian court festivals when women frequently played the parts of men but it was in late 17th-century France that the Paris Opera produced the first celebrated ballerinas.
Split into simpler sentences: In the Middle Ages, what has become known as ballet had its beginnings in Italian court festivals when women frequently played the parts of men. It was however in late 17th-century France that the Paris Opera produced the first celebrated ballerinas.