I read somewhere that Iran had the longest running dynasty in history, so I looked it up in Wikipedia.

Persia underwent a revival under the Safavid dynasty (1502-1736), the most prominent figure of which was Shah Abbas I. Some historians credit the Safavid dynasty for founding the modern nation-state of Iran. Iran's contemporary Shia character, and significant segments of Iran's current borders take their origin from this era (e.g. Treaty of Zuhab).
Not trying to politicize this thread, but that's pretty stable for a country that is allgedly trying to destabilize the region.

Cordially,