Sanatana Dharma or Vedic Dharma (Vedicism) is the proper name for Hinduism. The terms Hindu and Hinduism are misnomers, just as Mohammedan and Mohammedanism are misnomers for Muslims and Islam. The term Hindu is originally a geographic definition used by the ancient Iranians to label all the peoples living in the lands of the Indus Valley or east of the Indus River regardless of religious affinity or faith. The term Hindu was later adopted by the Arabs who conquered Sassanid Iran and then expanded towards the the Indian sub-continent. As the Altaic peoples, such as Mongolian and Turkic-speaking tribes, migrated westward in Eurasia they also adopted the term through interaction with both the Iranians and the Arabs. At this time in history and up to the rule of the Mugal Dynasty in India the term Hindu started gaining popular and recurrent usage, but was still used as an ethnographic term and not a religious identification label. The Muslims, Sikhs, Christians, Buddhists, and Vidicists of India were all called Hindus. It was during the colonial era that the British, who ruled India, coined the English-language term/word Hinduism and assigned the already existing and ancient Iranian term/word Hindu in 1830 to describe and designate the faiths and peoples of India belonging to Vedicism. Hindus are in reality all the people of India. The term Hindi, also used to label Indians and one of the main Indic languages, comes from Hindustani which also reflects the geographic nature and origins of the term Hindu; Hindustan means land of India and Hindustani people of India.