In Sanskrit texts, Raja yoga was both the goal of yoga and a method to attain it. The term was later adopted as a modern label for the practice of yoga when Swami Vivekananda gave his interpretation of the Yoga Sutras of Patanjali in his 1896 book Raja Yoga. Since then, Rāja yoga has variously been called ashtanga yoga, royal yoga, royal union, sahaja marg, and classical yoga.