The Musashi Province was one of the provincial territories that belonged to the Kamakura Bakufu where kokushi (provincial governors) were nominated by the shogun; many samurai groups existed there and it was strategically one of the most important locations for the defense of Kamakura.
武蔵国は将軍によって国司が推挙される関東御分国（将軍家知行国）の一つであり、数多の武士団が存在し、鎌倉防衛の戦略上の要地であった。