Linked from
The 38 pages that link to Kamakura shogunate, each with the reason it gives.
Ashikaga shogunateNarrower topic: Its collapse created the opening for Ashikaga rule.
Muromachi periodNarrower topic: Its collapse created the opening for a new military government.
Genkō WarNarrower topic: The war began as a challenge to this government’s authority.
JōkyūNarrower topic: Its victory in 1221 sharply increased its authority over the court.