In the broadest sense, the term "Muromachi period" refers to the 235-year span during which the country was at least nominally ruled by an Ashikaga Shogun, beginning when Takauji ASHIKAGA enacted the Kenmu Code in 1336 before formally creating the bakufu in Kyoto in 1338, and ending when Nobunaga ODA exiled the fifteenth Shogun, Yoshiaki ASHIKAGA, in 1573; however, both the early and late stages of the Muromachi period can also be classified as the Northern and Southern Courts (Nanbokucho) (Japan) and Sengoku periods, respectively, so many favor a narrower definition of the Muromachi period, in which it is limited to the span from the unification of the two courts (in 1392) until the outbreak of the Meio Coup (in 1492, or alternatively the outbreak of the Onin War in 1467).
広義には足利尊氏が1336年（建武(日本)3年）に建武式目を制定し、1338年に正式に京都に幕府を開いてから、15代将軍足利義昭が1573年に織田信長によって追放されるまでの235年間の足利将軍の存続期間を指すのが一般的であるが、前期を南北朝時代(日本)、後期を戦国時代(日本)とそれぞれ区分して、南北朝合一から明応の政変（あるいは応仁の乱）までを狭義の室町時代とする場合も多い。