n the period of the Northern and Southern Courts (Japan), the Shinano Ogasawara clan belonging to the Northern Court (Japan) defeated Imperial Prince Muneyoshi of the Southern Court (Japan) at the Battle of Kikyogahara and drove out in Yoshino, by which the clan played active role as hokoshu (the shogunal military guard) and Shinano shugo in the Muromachi period, however, because of out-of-control powerful local lords (kokujin) such as the Murakami clan and the Suwa clan, Nagahide OGASAWARA was defeated at the Battle of Oto and therefore the position of shugoshiki (provincial constable) was superseded by the Uesugi clan and the Shiba clan, and it couldn't lay out a strong controlling system.
南北朝時代(日本)になると、信濃小笠原氏は北朝(日本)に属し、桔梗ヶ原の戦いで南朝(日本)の宗良親王を破り吉野へ駆逐した戦功で、室町時代には一族が幕府の奉公衆や信濃の守護となり活躍したが、小笠原長秀が大塔合戦での敗北で守護職を罷免されるなど村上氏や諏訪氏などの有力国人の統制がうまくいかず、上杉氏や斯波氏に守護職を奪われ、強力な統治体制を整えることが出来なかった。