In 1956 the ballet company and school were granted a Royal Charter by Queen Elizabeth II, and formally linked. De Valois made sure that her company had a constant supply of talent, and in later years it had such stars as Svetlana Beriosova, Antoinette Sibley, Nadia Nerina, Lynn Seymour, and, most sensationally, Rudolf Nureyev. She also invited choreographers such as Sir Kenneth MacMillan and George Balanchine to work with her company. She formally retired from the Royal Ballet directorship in 1963, but her presence continued to loom large in the company, and the same was true with the School, from which she formally retired in 1970.