北周末年楊堅在毫無跡象的情形下突然興起代周，引起不少史家驚訝：「古來得天下之易，未有如隋文帝者。」為了解釋這種突起的變局，已往學者都強調楊堅之家世背景以及其婚姻關係，楊堅父楊忠在西魏府兵制度成立時為十二大將軍之一，北周時位至柱國、大 司空，楊堅之妻獨孤氏為西魏元勳武將、北周大益司馬獨孤信之女，楊堅之長女則嫁給北周宣帝，據此認為楊堅不但出身名門，又聯姻權貴，且具有外戚身分，因此在北周末年已有雄厚的個人勢力，終能篡周建隋。另外有的學者則從西魏北周漢族勢力之興起，強調楊堅出身弘農華陰之漢人名門家族，因而能夠得到勢力高張的漢族支持，終能結束北周胡族政權建立漢族的隋帝國。以上這些說法雖然不能說完全無據，但卻也難免有捕風捉影誇大其詞的情形。本文對以上論點，做較實證的檢討，認為楊堅之家世背景以及其婚姻關係，只是其出仕或高升的基本條件，而非決定性的要件，因此不宜做誇大的解釋，至於北周漢族勢力高張之說恐亦猜測的成分居多。另一方面，本文亦不認為楊堅之得位出於歷史的偶然性，而是認為楊堅得位的決定性要件，除了其具有非凡的才華掌握周末變局之外，北周政權已深藏的各種弱點，如過度的中央集權化體制、北周權力基礎的狹窄化、北周後期的弊政，如武帝廢佛道二教措施、宣帝刑法嚴酷等等，這些政權弱點被楊堅所充分利用才是決定性的要件。

　　　　　Unexpectedly overthrowing the Chou Dynasty, Yang Chien 楊堅 established the Sui Dynasty. This astonished many historians, as they felt that no one would ever be able to usurp the throne so easily and become Sui Wen-ti隋文帝. To illustrate such a drastic historical change, some historians focused on Yang Chien's family background, including the connections he established through his own and his daughters' marriages. Yang Chien's father, Yang Chung 楊忠, was one of the main twelve generals when the Western Wei's Garrison Militia system was established. During the Northern Chou, Yang Chien was promoted to Chu-kuo 柱國 and Ta-szu-k'ung 大司空. Moreover, Yang Chien married the daughter of Tu-ku Hsin 獨孤信, Western Wei' s veteran military commander and Northern Chou's Ta-szu-ma 大司馬, while his eldest daughter married Northern Chou's Hsuan-ti 宣帝. Thus, in the eyes of many scholars Yang not only came from an aristocratic background, but also intentionally allied himself with powerful and noble families, including that of the queen. In sum, Yang Chien gradually built up his family ties to usurp Northern Chou's power and establish the Sui Dynasty. Other scholars emphasize the rise of the Han people during the Western Wei and Northern Chou periods. As Yang Chien himself was a Han noble from Hua-yin in Hung-nung prefecture, he easily obtained the support of the newly powerful Han. In this manner he managed to overthrow Northern Chou, which the Han considered barbarian, to form the Han-Sui Empire. Although evidence exists to support the above claims, unavoidably much of it contains speculation and exaggeration. This article provides more valid proof, presenting a different historical perspective on the matter. TO begin with, the article shows that Yang's family background had little influence on his rise to power. Thus, the exaggerated explanations and suppositions about his background are inappropriate. Furthermore, theories about the rising influence of the Han in the Northern Chou are also mainly speculative. As a result, this article concludes that Yang's rise was by no means an accident, but rather due to his brilliantly taking control of the situation at the end of the Northern Chou Dynasty. The Northern Chou eventually showed weakness in many areas, such as over-centralization of power and an ever-diminishing power base. Mistakes in governing, such as Wu-ti's abandonment of Buddhism and Taoism, and Husan-ti's excessive system of corporal punishment, further weakened the Northern Chou. Yang Chien took advantage of problems like these to easily usurp the Northern Chou throne.