It was the Kamakura period.
The Shogunate was established by Yoritomo Minamoto. During this period,
Buddhism flourished and the Samurais proved themselves against the Mongols who
invaded Japan twice but failed each time.
Later the Shogun became the actual ruler of Japan.
The Middle age is known as the (Medieval Age or Dark age), so the Ancient Rome came before it.
It was due to conflict within the revolutionaries, weak support and allies, and not enough military support. Hope this helps!
It all represented like rebelion against taxes
