Yoga's origins can be traced to northern India over 5,000 years ago. The word yoga was first mentioned in ancient sacred texts called the Rig Veda. The Vedas are a set of four ancient sacred texts written in Sanskrit. The Rig Veda is the earliest amongst the Vedas and is a collection of over a thousand hymns and mantras in ten chapters known as mandalas, which Vedic age priests used. Yoga was refined and developed by Rishis (sages), who documented their practices and beliefs in the Upanishads, a huge work containing over 200 scriptures.
Yoga is among the six philosophy schools in Hinduism and is also a major part of Buddhism and its meditation practices. You can find out more about the history of yoga here from the Shri Yogendra Museum of Classical Yoga – the world's first museum dedicated to yoga.