The Talysh language (Tolışi / Толыши / تالشی زَوُن) is a Northwestern Iranian language spoken in the northern regions of the Iranian provinces of Gilan and Ardabil and the southern regions of the Republic of Azerbaijan. Talysh language is closely related to the Tati language. Historically, the language and its people can be traced through the middle Iranian period back to the ancient Medes. It includes many dialects usually divided into three main clusters: Northern (in Azerbaijan and Iran), Central (Iran) and Southern (Iran). There are a wide variety of estimates for the number of Talyshi speakers with reliable estimates running anywhere from 500,000 to 1 million. Talyshi is partially, but not fully, intelligible with respect to Persian. Talysh is classified as "vulnerable" by UNESCO's Atlas of the World's Languages in Danger.