Tehran is a relatively young city by the standards of Iran with its millennia of history. It only became a major city after it was made the capital in 1788 in the Qajar era. However, the area has been inhabited for thousands of years. Shahr-e Rey, just south of Tehran, was established over 3,000 years ago and is mentioned in the Zoroastrian holy book, the Avesta, and in the Catholic version of the Bible in the book of Tobit.