De Valois founded the Vic-Wells Ballet at Sadler's Wells Theatre, the company that evolved into The Royal Ballet.
On 5 January 1931, the Vic-Wells Ballet, founded by Ninette de Valois, gave its first performances at Sadler's Wells Theatre in London, marking the formal establishment of what would become one of the most important ballet companies in the world.
De Valois had been invited by theatre manager Lilian Baylis to establish a resident ballet company, building on the small school she had opened in 1926. This was a pioneering act: at the time, Britain had no significant native ballet tradition, with audiences accustomed to touring Russian and continental companies such as the Ballets Russes. De Valois set out to create a distinctly British classical ballet institution, training homegrown dancers and choreographers rather than relying on imported stars.
The company would go on to become Sadler's Wells Ballet, and eventually, in 1956, receive a Royal Charter to become The Royal Ballet. This foundational moment is considered the birth of British classical ballet as an institutional art form, and it overcame significant skepticism that Britain—unlike Russia or France—could produce a serious national ballet tradition. De Valois's vision, discipline, and administrative acumen were instrumental in this success, and the company remains a cornerstone of world ballet today.