List of ancient great powers
The Sassanid Empire is the name used for the fourth Iranian dynasty, and the second Persian Empire (226–651). The empire's territory encompassed all of today's Iran, Iraq, Armenia, Afghanistan, eastern parts of Turkey, and parts of Syria, Pakistan, and large parts of Caucasia, Central Asia and Arabia. During Khosrow II's rule in 590–628 Egypt, Jordan, Palestine, Lebanon were also briefly annexed to the Empire, as well as far west as western Asia Minor. The Sassanid era, encompassing the length of the Late Antiquity period, is considered to be one of the most important and influential historical periods in Iran. In many ways the Sassanid period witnessed the highest achievement of Persian civilization. The empire is furthermore known for being the arch-rival of the neighboring Roman–Byzantine Empire for a period of over 400 years. As the Parthians were replaced by the Sassanids, they carried on the already century long lasting Roman–Persian Wars, which would eventually become the longest conflict in human history.
France–Iran relations
A Franco-Persian alliance was formed for a short period between the French Empire of Napoleon I and the Persian Empire of Fath Ali Shah against Russia and Great Britain between 1807 and 1809. The alliance was part of Napoleon's plan to create another front on Russia's southern borders, as Iran and Russia were directly bordering each other there in the Caucasus region. Furthermore, the Iranian king was involved in a territorial dispute with the Russian tsar following its annexation of Georgia, which had been intermittently part of Iran since the mid 16th century. The alliance unravelled when France finally allied with Russia and turned its focus to European campaigns, and dropped its support during the Russo-Persian War (1804-1813), which eventually turned out into an Iranian defeat and huge irrevocable territorial losses, comprising modern-day Georgia, Dagestan, and most of the contemporary Republic of Azerbaijan.