Short answers, pulled from the story.
Ballet originated in the year 1489 during a wedding feast in the Italian town of Sabbioneta. This early court ballet known as the intermedio featured noble amateurs performing in heavy costumes woven from cotton, silk, and flax.
King Louis XIV of France founded the Académie Royale de Danse in 1661. He appointed Jean-Baptiste Lully as director of the Académie Royale de Musique in 1672 and worked with Pierre Beauchamp to create the five major positions of the feet.
Romantic ballet began in the early nineteenth century with the 1827 ballet La Sylphide considered the first true Romantic ballet. This era prioritized intense emotion and the supernatural while introducing pointe work and longer flowy tutus designed to exemplify softness.
Agrippina Vaganova developed the Vaganova method at the Leningrad Choreographic School starting in 1921. Her book The Fundamentals of Classical Dance published in 1934 fused the classical French style with the athleticism of the Italian method to emphasize strength and flexibility.
George Balanchine developed the Balanchine method in the United States which prioritizes extreme speed deep pliés and unorthodox body positioning. His work such as Apollo in 1928 is considered the first neoclassical ballet and is taught at institutions like the School of American Ballet.
Professional ballet dancers earn an average of US$19 per hour as of 2020 and face health issues including stress fractures in the first rib and posterior ankle impingement syndrome. The profession also carries a high risk of eating disorders and results in lower bone mineral density in the arms due to intensive training.