Caviar sturgeon from the Sea of Azov began reaching the tables of aristocratic and noble Byzantine Greeks in the 10th century, after the commencement of large-scale trading between the Byzantine Empire and Kievan Rus'. The main types of caviar are Beluga, Sterlet, Kaluga hybrid, American osetra, Ossetra, Siberian sturgeon and Sevruga. The rarest and costliest is from beluga sturgeon that swim in the Caspian Sea, which is bordered by Iran, Kazakhstan, Russia, Turkmenistan, and Azerbaijan. Wild caviar production was suspended in Russia between 2008 and 2011 to allow wild stocks to replenish. Azerbaijan and Iran also allow the fishing of sturgeon
The Three Types of Legitimate Rule and they directly contribute to the state system stability and authority. All rulers have an explanation for their superiority, an explanation that is commonly accepted but during a crisis can be questioned. Weber sees only three categories of legitimation strategies (which he calls "pure types") used to justify the right of rulers to rule: The types of authority change over time, when the ruled are no longer satisfied with the system. For example, after the death of a charismatic leader his followers, if they lack the charisma of their predecessor, will try to institute a system based on tradition or